As E. Cortese notes at the beginning of his article on I. in DBI, I. is better known for the insoluble problems that his biography presents than for the quantity of datable facts about his life. Or, as Jean Gaudemet put it more than fifty years ago (‘Review’ 654): ‘L’extrême rareté des sources laisse la porte ouverte à bien des hypothèses, que l’on veuille décrire les formes premières de l’enseignement bolonais ou préciser l’apport d’Irnerius à cette renaissance.’

By the middle of the 13th century much could already have been legend. Odofredus († 1265), commenting on Dig. 1.1.6, describes I. (critical ed.; E. Kantorowicz in E. Kantorowicz and B. Smalley, 238, adopting the reading of ed. Lyon 1570, fol. 7rb, and Firenze, BN Magl. XXIX, fol. 27f, for the last phrase of the penultimate sentence [‘forsan rectius’ in K’s apparatus] and that of ed. Lyon for the last sentence, which K. did not edit):

Or signori, dominus Yrnerius fuit apud nos lucerna iuris, fuit enim primus qui docuit iura in civitate ista. Primo cepit studium esse in ciuitate ista in artibus, et cum studium esset destructum Rome, libri legales fuerunt deportati ad ciuitatem Rauenne et de Rauenna ad ciuitatem istam. De hoc studebantur in artibus libri legales, qui a civitate Ravenne fuerunt·portati ad civitatem istam. Quidam dominus Pepo cepit autoritate sua legere in legibus, tamen quicquid fuerit de scientia sua nullius nominis fuit. Dominus Irnerius docebat in civitate ista in artibus, cepit per se studere in libris nostris, et studendo cepit velle docere in legibus. Et ipse fuit maximi nominis et fuit primus illuminator scientie nostre, et quia primus fuit qui fecit glosas in libris nostris ipsum lucernam iuris nuncupamus. Unde dominus Yr. lucerna iuris super lege ista scripsit glosam interlinearem elegantissimis verbis, et bene dicit ipse ista litera dicit ‘ius ciuile est quod neque a iure naturali vel gentium in totum recedit nec per omnia ei seruit’.

Although this edition has been in print since 1943, it is rarely quoted, preference being given to the printed edition of 1570. In particular, the critical edition has a whole sentence that the edition of 1570 lacks, the one beginning ‘De hoc’. This may turn out to be relevant when we get to the question not whether I. taught but how he taught.
How much of Odofredus’ account can be believed? A medieval law school in Rome shortly prior to that at Bologna is a ‘phantom’ (E. Cortese, in DGI, but cf. L. Loschiavo, ‘Was Rome still a Centre of Legal Culture between the 6th and 8th Centuries?’). If we take Odofredus as referring to something that happened centuries before his time, there may be some truth to what he says. It is possible that the manuscripts that were used in the studium at Bologna had their ultimate origins in Ravenna (see G. Nicolaj, ‘Documenti e libri legales a Ravenna’ 778–797). That does not correspond with what we know about the migration of the codex Florentinus (see G. Purpura, ‘Littera florentina’), but the use of that manuscript in the creation of the Bolognese version of the Digest does not seem to have come until quite late (Müller, ‘Digest’ 3–4). That a lawyer or legal scholar called ‘Pepo’ existed is certain, though little is known about him (Cortese, in DGI, s.n.). What do we know for certain about I.?

Although there are those who have doubted the connection, we can probably equate him with a man who usually signed himself ‘Wernerius’. His contemporaries turned that into ‘Warnerius’, and then made Romance out of it, ‘Garnerius’ or ‘Guarneius’, with many variants that add up linguistically to the same thing. ‘Irnerius’ or ‘Yrnerius’ are not found until after his death (F. Patetta, 147–151). The name is obviously Germanic, and I’s own spelling corresponds – with a Latin suffix – to the more common spelling of the name among German-speakers today. That a late 12th-century Summa quaestionum (K. W. Nörr) and a mid- to late 13th-century additio to Dig. 1.2.2 by a student of Franciscus Accursius († 1293) (G. Pace) calls him ‘theutonicus’ probably does not tell us much that we did not already know. It could refer to I’s place of origin, but it need not.

What do we know about this Wernerius, Warnerius, Garnerius, Guarnerius? He was not the only person with that name who was operating in Italy in the early years of the 12th century, and distinguishing him from the others is a delicate task. In 1970, E. Spagnesi edited 14 documents that subsequent scholarship has accepted as referring to the same man, the one who could have been a teacher of law at Bologna, though no contemporary document says that he was. (Landulfus iunior does call him ‘magister’.) This man appears in 1112 and 1113 as causidicus in pleas at Cornacervina and at Baviana (the latter presided over by Matilda of Canossa) (E.Spagnesi, Wernerius nos. 1–2). Between 1116 and 1118, a iudex Bononiensis of I’s name was in the retinue of Henry V during his second journey to Italy (E.Spagnesi, Wernerius nos. 3–13, a number of which contain his autograph). In the last charter of December 1125, I. continues to be called a Bolognese judge and assisted the monastery of Polirone (patronized by Matilda of Canossa) in an arbitration (E.Spagnesi, Wernerius no. 14; Codice polironiano, 331–335). R. Rinaldi, the editor of Codice polironiano, expressed doubts about this charter; but K. Pennington has convincing arguments that it is genuine (‘Irnerius’, 108–109).

Landulfus iunior, writing in the early 12th century, tells of an intervention of ‘magister Guarneius de Bononia et plures iuris periti’ in the election in March 1118 at Rome of Maurizio Bourdin, the antipope Gregory VIII (MGH SS rer. ger. 20, c. 45, p. 40). The council of Reims excommunicated I. on 30 October 1119 when he was probably in Germany in the retinue of the emperor (W. Holtzmann, ‘Investiturstreit’ 319). (In a document of August 1118 he is at Treviso, probably heading toward the frontier [E. Spagnesi, Wernerius no. 13].) The excommunication was revoked probably when that of Henry V was revoked, and in 1125, he is supposed to have been in Italy again. (For an analysis of the entire episode and its legal implications, see most recently O. Condorelli, ‘L’Elezione’. E. Cortese in DGI dates the reovocation of the excommunication to 1120 without reference, Condorelli to the reconciliation of Henry V with Callixtus II, probably in 1122.)

If these references seem to be dealing with our I., other references to a man of that name are more problematic. An interpolation that Robert of Torigni made to the chronicle of Sigebet of Gembloux († 1112), sometime between the mid-1150s and Robert’s death in 1186, reads under the year 1032 (ed. T. Bisson, 2.180–183):

Lanfrancus Papiensis et Garnerius socius eius, repertis apud Bononiam legibus Romanis, quas Iustinianus imperator Romanorum anno ab incarnatione Domini.d.xxx. abbreuiatas emendauerat; his inquam repertis, operam dederunt eas legere et aliis exponere. Sed Garnerius in hoc perseuerauit, Lanfrancus uero disciplinas liberales et litteras diuinas in Galliis multos edocens, tandem Beccum uenit et ibi monachus factus est, sicut in squentibus potest repereri.

If we take the year as being 1032 and the Garnerius being referred to as our I., this cannot be be right. Lanfranc left Pavia in 1030s, which has to be before our I. was born, and Lanfranc never again taught law. E. Cortese in DGI speculates that Robert got Garnerius confused with Gualcosius (Walcausa), a well-known exponent of Lombard law in the period. A. Padovani has argued that we need not take socius chronologically (we might add that socius does not necessarily mean ‘student’) and that there are connections between I. and Lanfranc that we should take seriously (e.g., in ‘Alle origini’ 18–22). Some support for this view may be found in the fact that Robert’s text is, as Bisson emphasizes, an interpolation in a chronicle that is organized strictly chronologically. Robert wanted to say that Lanfranc was involved in the teaching of Roman law, and he has to put it under a date that predates Lanfranc’s leaving Italy. He also wants to say that teaching of Roman law continued in Italy, and he wants to associate that teaching with Bologna and a man named Garnerius. There may be more historical truth in what Robert has to say about I., about whom he could have learned from Vacarius, than about what he has to say about Lanfranc’s teaching of Roman law (see Bisson, p. lvi–lvii, but cf. E. Cortese, ‘Lanfranco di Pavia’, who remains of the view that Robert got I. mixed up with Gualcosius, though he accepts the idea that Lanfranc was making arguments about Roman law while he was at Pavia).

More problematic is the identification of our I. with the Guarnerius de Brigey (probably modern Briey, dép. Meurthe-et-Moselle), a functionary of the countess Matilda who was present at Guastella on 10 March 1106 (C. Dolcini, ‘Postilla’ 98–100; G. Mazzanti, ‘Irnerio’ 158–159). What makes the identification problematic is that our I. is nowhere else called ‘de Brigey’. In the list of the excommunicates at Reims, his name is preceded by a man who is described as ‘de Brierio’ (which Grässe identifies as Briel-sur-Barse [dép. Aube], but which may, alternatively, be Briey); I., however, is described as ‘Gwarnerius Bononiensis legis peritus’ (W. Holtzmann, ‘Investiturstreit’ 319). Even more problematic is the identification of our I. with the Warnerius presbiter who occurs in a document from Piadena of 21 May 1095 and in another of 14 May 1101 (G. Mazzanti, ‘Irnerio’ 155–158). According to E. Cortese in DGI, the rule at the time seems to have been that judges of secular tribunals, which our I. clearly was, had to be laymen.

That brings us to the Guarnerius who is identified as the author of a Liber divinarum sententiarum, a florilegium of patristic texts, principally by Augustine. The copyist of one of the three surviving manuscripts added an interlinear gloss that identified the author as ‘legisperitissimus’. The work has been known for some time. Most scholars doubted that the Guarneius of the Liber was the same as our I. To base an attribution on the basis of an identification of a copyist who had heard of a ‘Guarnerius legis peritissimus’ but who may have had no idea who the Guarnerius was whose work he was copying is to rest on a pretty slender reed. (For an elaborate counter-argument, see G. Mazzanti, ‘Introduzione’, in Liber divinarum sententiarum 1–36, 60-87.) The identification, however, has its recent defenders in addition to Mazzanti, who edited the text: C. Dolcini (cited by E. Cortese in DGI without specific reference), E. Spagnesi (Libros legum renovavit 128–149), and, particularly, A. Padovani (‘Alle origini’ 20–21 and n. 14 [a long list of supporters], and elsewhere [see Literature]), who has used the identification to suggest an intellectual context for the studium at Bologna more ecclesiastical than it is normally thought to have been.

While it is possible that our I. had a youthful interest in theology, we should remember that there were a number of men with his name who were operating in Italy in his period. In addition to the ones mentioned above whom we doubted, sometimes strongly, were the same man. A Warnerius was a judge delegate of Henry IV at Monselice in May 1100 (I placiti del “Regnum Italiae” 3.2.444–446). He is perhaps the same man as the one who, at an uncertain date, is referred to as a comes (E. Spagnesi, Wernerius 160–162). He is probably not our I. There is a magister Garnerius in a Sicilian charter of 1117 (E. Besta, L’opera 1.49). Nothing that we know of our I. would connect him with Sicily. The obituary of the monastery of Saint Victor in Paris registers, among many others, on 19 September of an unspecified year, a ‘magister Garnerius teutonicus de cuius beneficio habuimus quinque libros optimos glosatos’ (G. Mazzanti, ‘Irnerio’ 128). To base the identification with our I. on the supposition that the five books given were the five libri legales is hazardous. The division of the Justinianiac corpus into the five volumes as we know them did not happen until after I’s time. Indeed, the creation of the volumen parvum postdates Accursius (L. Loschiavo, ‘Verso la costruzione’ 444-445.) Many philosophical, theological, and literary works with glosses were in circulation at the time. Once we get outside of Italy, the name Garnerius becomes even more common than it is in Italy. The tenth abbot of Marmoutier was named Garnerius (Robert of Torigni, ed. Bisson, 1.192–193, 2.274–275) as was the fourth abbot of La-Croix-Saint-Euvroy (idem, 2.264–265). They are certainly not our I.; neither is likely to be the Garnerius of the obituary.

A mid- to late 13th-century additio to Dig. 1.2.2 tells of I’s departure from teaching ‘per nimiam senectutem’ and another of his return ‘ad domum suum’, perhaps his transalpine homeland (G. Pace, 125–126, 131 and n. 23). A death date between 1130 and 1140 is plausible, but by no means certain.

The certain identifications with dates give us an account of a lawyer of the early 12th century, a causidicus in 1112 and 1113, perhaps associated the countess Matilda († 1115), a iudex in 1116, 1117, and 1118, and still called a iudex in an arbitration of 1125. After the death of the countess Matilda, he was associated with Henry V and ran into a buzz saw at the council of Reims in 1119, but he was reconciled with the church, a reconciliation that we may associate with Henry’s own reconciliation with Callixtus II. I’s appearance at Polirone in 1125 suggests that he was also reonciled with followers of Matilda.

Can we identify this man with the I. of later tradition, the founder of legal studies at Bologna, the ‘lamplight’ of the law? It is not easy to do so, and the difficulty of doing so has prompted some recent scholars (R. W. Southern, 1.279–280; J. Fried, Entstehung 102–103; idem, ‘. . . auf Bitten der Gräfin Mathilde’ 173–174; A. Winroth, Making 147–148; idem, ‘Les deux Gratien’, idem, ‘Teaching’ 41–44) not simply to deny the connection but to argue that legal studies at Bologna did not begin until Bulgarus, the oldest of the ‘four doctors’. This argument has met with a strong reaction, illustrated, perhaps led, by K. Pennington and A. Padovani, who adhere, in different ways, to the traditional view that I. did indeed teach law at Bologna, that he did so about a generation before Bulgarus and Gratian, and whether he taught them all or not, was succeeded by ‘the four doctors’ from whom we can trace chains of masters and students throughout the Middle Ages and even to the present day.

This is not the place to try to settle the ongoing scholarly debate. We can, however, give some sense for the arguments. Not the least of the difficulties is how to explain how a man called variously Wernerius, Warnerius, Garnerius, or Guarnerius became consistently the Irnerius or Yrnerius of the tradition. Unlike the shift from Wernerius and Warnerius to Garnerius or Guarnerius for which there are solid linguistic reasons if we assume that the overwhelming majority of those who made the shift were native Romance speakers, there is no linguistic reason why they should have dropped the initial consonant entirely.

The easiest explanation for the change is that the vast majority of the early manuscripts use ‘y’ or ‘yr’ as I’s siglum. (‘W’ or ‘G’, sometimes with a following ‘er’ or ‘r’ is found, but in a decided minority of the citations.) But that simply raises the question where did the ‘y’ come from? Various efforts to show how it might have been derived from a misreading of ‘W’ or ‘G’ are ingenious (e.g., G. Nicholaj, ‘Documenti’ 795) without being totally convincing. Such things do happen, however; one is reminded how the ‘D’ for ‘Digesta’ got misread as ‘ff’ in later manuscripts and in all the early prints. Even more depressing is the suggestion that the ‘y’ is not a corruption of ‘W’ or ‘G’ but is a section mark or asterisk, put in to separate the base text from the gloss and found, as it frequently is, at the beginning rather the end of the gloss. At the beginning of the tradition, there was no need to separate I’s glosses from those of others. His were the only ones. Or – and this is what makes the suggestion depressing – is it that at the beginning of the tradition the authority of the master is not that important, and the glosses are the result of a team effort? This possibility is enhanced by the recent work of H. Jakobs who examined all the manuscripts of a particular gloss on the Digestum vetus and discovered that some of them attributed it to ‘y’, some to Martinus, and many to no jurist at all (‘Irnerius’ Sigle’ 450–460). (G. Dolezalek, ‘Review’ 497, adds a more elaborate argument based on the ‘y’s’ found after I’s signature, where the ‘y’ has to be a flourish or a section mark.)

All that said, we have to account for a consistent tradition that identifies I. as the ‘founder’, at least at Bologna, of the teaching of law. He may not have been the ‘Guanerius bononiensis iudex’ of the documents, but Ockham’s razor would suggest that it is more likely than not that he was. Otherwise, we would have to posit a man with approximately the same name who is otherwise unknown.

More problematic is whether I. was doing quite the same thing as what Odofredus was doing. Odofredus does not say that he was. What Odofredus does say in the passage quoted above was that I. was teaching arts before, perhaps even while, he taught law. He is more sure, perhaps too sure, of the chronology in his comment on Cod. 2.21.9: ‘Dominus Yr., quia logicus fuit et magister fuit in civitate ista in artibus antequam doceret in legibus, fecit unam glosam sophysticam que est obscurior quam sit textus’ (Lyon 1550, fol. 101va). A teacher of grammar, logic, and rhetoric fits well with many of the ‘y’ glosses. They focus on what we might call the philological: the meaning of obscure terms, the logic of the passage, cross-references to similar passages. They are also written by one whom we might imagine was an accomplished rhetorician, normally clear, simple, and precise. They are the work of a man who had a sense for the rhetoric of juristic texts.

Within a short time after his death authors who were not operating in the legal tradition recognized I. as a teacher. Writing probably in the late 1160s or early 1170s, the third of the authors who goes under the name of Otto Morena, describing the supposed appearance of the ‘four doctors’ at Roncaglia sometime in the mid-1150s, tells us: (MGH, SS rer. Germ. N.S. 7.58–59):

Istorum autem quatuor doctorum et quam plurium aliorum fuit dominus et magister dominus Guarnerius, doctor antiquus. Ad quem, cum in extremis laboraret, accesserunt sui scollares dicentes: ‘Domine, quem vultis post mortm vestram doctorem nobis constituere?’ Quibus ipse respondit per duo carmina infrascripta:

‘Bulgarus os aureum, Martinus copia legum

Mens legum Ugo, Jacobus id quod ego.’

We need not believe that anything like this happened. The story is a reworking of a story told by Aulus Gellius about the death of Aristotle (Attic Nights 13.5.1-3). It is followed by the equally apocryphal story of the emperor Frederick Barbarossa and the jurists Bulgarus and Martinus that ends in a triple pun about the loss of a horse. What we probably should believe is that at Lodi, where the Morenas operated, a hundred miles from Bologna, a generation after his death, I. was regarded both as a great teacher and as the teacher of the ‘four doctors’.

A decade or two later (before 1189), the English theologian and prolific author Radulfus Niger, writing in Paris, says (H. Kantorowicz and B. Smalley, 252):

Cum igitur a magistro Peppone velut aurora surgente iuris Civilis renasceretur initium, et postmodum propagante magistro Warnerio iuris disciplinam religioso [s]cemate traheretur ad curiam Romanam, et in aliquibus partibus terrarum expanderetur in multa veneratione et munditia, ceperunt leges esse in honore simul et desiderio . . . .

That is not, of course, the comparative assessment of Pepo and I. that Odofredus gives, but Niger does recognize that I. ‘propagated’ (?taught) civil law.

The most interesting notice of I. by a non-lawyer is, unfortunately, the latest. Writing probably in the late 1220s, Burchard of Biberach, provost of Ursperg, says (MGH, SS rer. Germ. 23.342):

Huius temporibus magister Gratianus canones et decreta, quae variis libris erant dispersa, in unum opus compilavit adiugensque eis interdum auctoritates sanctorum patrum secundum convenientes sententia opus suum satis rationabiliter distinxit. Eisdem quoque temporibus dominus Wernerius libros legum, qui dudum neglecti fuerant nec quispiam in eis studuerat, ad petitionem Mathildae comitissae [? at their meeting at Baviana in 1113] renovavit et, secundum quod olim a divae recordationis imperatore Iustiniano compilati fuerant paucis forte verbis alicubi interpositis, eos distinxit.

Burchard then goes on to describe quite accurately the four parts of what a later age will call the Corpus Iuris Civilis.

In the previous paragraph Burchard has just spoken of the coronation of Lothair III as Holy Roman Emperor in 1133, but the temporal reference at the beginning of this paragraph need not refer to that date. Lothair had been duke of Saxony since 1105. The following paragraph goes on to say that St. Bernard of Clairvaux (1090–1153) and St. Norbert (1075–1134) were distinguished (claruerunt) ‘illis temporibus’.

Burchard spent some time in Rome in the late 12th and early 13th centuries (M. Herwig, in Encyclopedia of the Medieval Chronicle, s.n. ‘Burchard of Ursperg’ [Brill online]). The story about the countess Matilda may have been circulating in Rome at the time. It certainly looks as if he had seen manuscripts of Gratian and early manuscripts of the libri legales. His description of Gratian’s contribution – ‘adiugensque eis interdum auctoritates sanctorum patrum secundum convenientes sententia opus suum satis rationabiliter distinxit [in the sense of ‘adorn’]’ – looks like a description of the dicta Gratiani, whereas his description of I’s contribution to the libri legales – ‘paucis forte verbis alicubi interpositis eos distinxit’ – would fit well with manuscripts that had I’s interlinear glosses or with short glosses set out with section marks in the text or in the margins as in the first layer of glosses in the Institutes in Vat. lat. 8782 (see K. Pennington, ‘Constitutions of Roger II’ figures 6 and 7).

That Burchard accurately described manuscripts that existed in his time does not, of course, mean that he got the chronology right. It is, however, interesting, and perhaps significant, that he regards Gratian and I. as contemporaries, the former working on canon law the latter on Roman.

What did I. write other than the problematic ‘y’ glosses? In the 19th and early 20th centuries what E. Cortese in DGI describes as a ‘fairy-tale castle’ of works were ascribed to I: the Brachylogus, the Epitome Exactis regibus; H. Fitting treated as I’s the Quaestiones de iuris subtilitatibus, the Summa Codicis Trecensis, a brief De aequitate, part of a De natura actionum, and finally the Summa legis Langobardorum; G. B. Palmieri ascribed to him the Summa Institutionum Vindobonensis and a Formularium tabellionum. As early as 1895, F. Patetta cast serious doubts on most of these, particularly Fitting’s, attributions (‘Delle opere recentemente attribuite ad Irnerio’). In 1938, H. Kantorowicz put the nail in the coffin, dismissing Fitting’s attributions in the words of Mommsen writing a half-century earlier about Fitting’s work on classical Roman law as ‘somnia Fittingiana’ (Studies, 145). Today, with Kantorowicz (Studies, 59–65 and 240; 46–50 and 233–239), the only works independent of the glosses that we can ascribe to I. are an Exordium Institutionum, a Materia Codicis, and, independent of Kantorowicz, a distinctio about the actio locati attributed to him by Roffredus (Savigny, Geschichte 4.469–470.) and, at the request of the notaries Angelo and Bonanno, a new formula for grants in emphyteusis to replace the form from Ravenna found in the old Bolognese formularies (but not the entire Formularium tabellionum) (E. Cortese in DGI; G. Nicolaj, ‘Arcana iuris’ 86–87 and n. 29).

A gloss on Cordi nobis (the promulgation decree of Justinian’s second Codex in 534), attributed to ‘y’ and taken by the later jurists who wrote about it to be by I., says that the author did not consider the text of the Authenticum to be, as it were, ‘authentic’ (Savigny, Geschichte 3.491–499; L. Loschiavo, ‘Riscoperta’ 129; K. Pennington, ‘Irnerius’ 115–118). It lacked a promulgation decree; it was too disorganized and prolix in comparison with the Codex. I. is supposed to have changed his mind because some, perhaps many, of the excerpts of the Novels (authenticae) placed at the end of the constitutions in the Vulgate text of the Codex are attributed to him (an attribution that Tamassia doubts [Odofredo 100, repr. 2.400–401]), but no one, and certainly not I., says that he changed his mind. In some sense, of course, the gloss on Cordi nobis is right. The Novels were privately, not officially, collected, at the end of Justinian’s reign or shortly thereafter. In comparison with the Codex, they are prolix, but that may be because the texts in the Codex, at least the later ones, were abbreviated, whereas many, if not most, of the Novels, as we now have them, are the complete text. To the extent that there is any order, it is chronological not topical. We must also remember that in the early 12th century, the text of the Authenticum was fluid. The transition from the Epitome Juliani to the Authenticum to the modern Novels was a gradual process, and some of the texts on which I. based his judgment were probably pretty bad. Be that as it may be, it seems reasonably clear that I. participated in the process of adding the authenticae to the Codex. He may even have started the process. He seems to have regarded the text of the Authenticum as evidence that Justinian had made a change, but not firm evidence of what change he made. Some of what appears in the early manuscripts as an authentica is quite far from what we now know that the Novel says. It got closer as time went on and as the text of the Authenticum got better. (See L. Loschiavo, ‘Riscoperta’; K. Pennington, ‘Irnerius’.)

There are many collections of I’s glosses in print. They are listed below in Texts. Granted the problematic nature of the ‘y’ siglum, they all need to be checked in the manuscripts to make sure that they are probably his, a task made more difficult by the fact that the Bolognese professor Henricus de Baila, a contemporary of Placentinus, used the siglum ‘Yr’ (H. Lange, Glossatoren 214). K. Pennington (most notably in ‘Odofredus and Irnerius’) has recently argued for genuineness of at least most of the ‘y’ glosses. It seems unlikely that they all are not I’s, or, at a minimum, were thought to be his at a fairly early date. Glossing is frequently connected with reading, and reading is frequently connected with teaching. Firm proof that I. taught at Bologna is lacking, but it seems highly likely that he did.

If I. taught at Bologna, when did he teach? The traditional date is that he began late in the 11th century or very early in the 12th. The traditional date was strongly influenced by a desire to connect the beginning of law teaching at Bologna with the ‘discovery’ of the Digest. We are now quite comfortable separating the two. An extensive collection of excerpts from the Digestum vetus appears in the Collectio Britannica (c. 1090) (Conrat, Pandekten- und Institutionenauszug 8–11). These are the source of the quotations by members of the circle of Ivo of Chartres in the late 11th century (e.g., Ivo, Decretum 16.74–75, 78–79, 103, 163–175, 177–184, 192–193: Preliminary ed. [online]). So far as we can tell, none of the men involved in this effort ever went near Bologna. The Digest also appears in 11th-century practice documents. Dig. 4.6.26.4 is quoted in a placitum associated with Matilda of Tuscany in 1076 (Müller, ‘Digest’ 2 and n. 3). Indeed, the Digestum vetus may have been known at Pavia as early as the 1030s (E. Cortese, ‘Lanfranco di Pavia’). Cortese even suggests that Lanfranc is the link that connects the Digestum vetus with the men of the north in late 11th century.

More to the point about I. is the argument of H. Kantorowcz. He says of Bulgarus’ teaching: ‘it would not be safe to assume a later date than 1115 as the terminus post quem’ (Studies 69). He gets to that date by backing up from Bulgarus’ famous letter to Aimericus, the chancellor of the Roman church, a letter that Kantorowicz assumes was written by a man who was well known as a teacher of Roman law and who must have achieved that status after long years of study. (Considering that Bulgarus and Aimericus were friends, Bulgarus may not need to have been so prominent at the time.) Assuming that the letter was written in the early 1130s (which it probably was [see K. Pennington, ‘“Big Bang”’ 49–52]), back up 15 years for the long years of study, and we get to someplace around 1115. Bulgarus was taught by I. Back up at least 15 years from Bulgarus’ beginning to teach, and we get to 1100, or even earlier.

The argument has some elements of Ptolemaic epicycles. In particular, it assumes that teaching involves an authoritative master and students, and that the students do not start to teach, at least in the same school, until after the master has ceased teaching. That may have been the situation later on. It does not necessarily have to have been the situation at the very beginning of the ‘school’. Indeed, what may have happened is something much more informal than what we think of when we use the word ‘school’.

The known dates of Wernerius, Warnerius, Garnerius, Guarnerius run from 1112 to 1125. He probably made a trip to Germany around 1119. He probably was not teaching when Henry V was in Italy between 1116 and 1118. There is nothing in the record that suggests that he could not have been teaching before that four-year period, or after it, or both.

Bulgarus died c. 1166 when he is said to have been a very old man, but he may have been what we call today a ‘mature student’ when he studied with I. Martinus died c. 1160, and nothing is said about his age. Hugo died c. 1168. Jacobus de Porta Revennate died in 1178, the only one of the ‘four doctors’ for whom we have a firm death date. If I. taught Jacobus – which is not at all certain – it is hard to imagine that he did so before 1116. Indeed, the later that we extend I’s teaching, the more comfortable becomes the tradition that he taught the ‘four doctors’. We need not accept in full the idea proposed by G. Nicolaj (‘Documenti’ 775, cf. ‘Arcana iuris’ 87–88) that I. did all of his teaching after 1119 or 1125, though her account of I’s life has considerable plausibility. All we need to posit is that he did some teaching after his excommunication and absolution. Even if we have I. teaching into the 1130s, that would not falsify the later tradition that he retired because of advanced age and ‘went home’, presumably to some place other than Bologna. Nothing in the later tradition says when that happened.

If this chronology is plausible, that would mean that I. and Gratian overlapped. That would fit quite well with what we now are inclined to believe about the gradual incorporation of Roman law into Gratian’s thought and text.

There remain many difficult questions, of which we flag three: (1) The identity of I. with the author of the Liber divinarum sententiarum is hard to prove, but the attempt to do so has raised many interesting questions about I’s intellectual context. The practicing lawyer of E. Cortese’s Rinascimento giuridico medievale, who started to read the libri legales in order to help notaries, advocates, and judges do their mundane jobs, sits somewhat uneasily with O. Condorelli’s intellectual sparkplug of the election of Gregory VIII, even more uneasily with A. Padovani’s genius who participated in the debate between Lanfranc and Berengar of Tours about transubstantiation (see, particularly ‘Matilda e Irnerio’), and even with G. Nicolaj’s hunter for manuscripts of what became the Corpus Iuris Civilis. Perhaps it is I. (pace R. W. Southern), the early 12th-century humanist, the teacher of arts, who ties them all together.

(2) Those who are interested in the high politics of the investiture controversy tend to find I’s association both with Matilda of Canossa and her party and with Henry V puzzling. Lawyers may find it less puzzling: you make the best arguments available for your clients, without necessarily committing yourself to all that your clients stand for. If that is even half right, I. may have been a professional lawyer before professional lawyers existed. Be that as it may be, the closer that we bring Gratian to Irnerius in time the less puzzling it is that Gratian says virtually nothing about the investiture controversy. He saw what happened to I., and he stayed away from it.

(3) The more early references that we find to the libri legales, particularly to the Digest, in canonical collections, secular legislation, and practice documents, the harder it is to believe that all the men who were making the references studied at Bologna. Not all teachers in the late 11th and early 12th centuries taught in what we would regard as schools; certainly not all of them founded schools that lasted. I. probably did found a school that lasted, though he may not have been aware that he was doing so. That, however, does not mean that the school did not change shortly after his time. While we need not, and probably should not, accept A. Winroth’s total skepticism about I’s teaching, Winroth does have a point when he argues (particularly in ‘Law Schools’) that Gratian and Bulgarus’ use of hypothetical cases turned whatever I. was doing into a proper law school.

Source: E. Cortese, in DGI 1.1109–1113, revised by CD

Entry by: CD 2.ii.2023