[003] When it is safer for the tenant to vouch a warrantor than to undertake the defence in [004] his own person, since no exception, peremptory or dilatory, wherewith to destroy the [005] action completely or defer it temporarily, lies for him, then, if he has a warrantor, let [006] him vouch him at once, sometimes by the aid of the court sometimes without it, according [007] as the warrantor is within the vouchor's potestas, so that he may have him [008] without aid, or within another's, so that he cannot produce him without aid.1 [009] Within another's potestas, I say, as within the potestas of the lord king, in the realm of [010] England or in Ireland or in Wales, in some place under the dominion of the lord king. [011] If he who is vouched is outside the potestas of the lord king, he will be vouched in [012] vain by aid of the court, because the tenant will then have to produce him himself, if [013] he can, otherwise he will lose.2
What warranty is.
[015] We must first see what warranty is. It is clear that to warrant is nothing other than to [016] defend and acquit the tenant who has vouched the warrantor in his seisin, for though [017] the warrantor warrants, seisin is not thereby transferred to him, nor is anything [018] transferred except the defence of the thing claimed, which defence, when it has once [019] been given over to the warrantor, cannot thereafter be resumed by the tenant, everything [020] proceeding in the name of the warrantor; nor may he, after he has warranted, [021] render the thing warranted to the demandant against the tenant's will or without [022] judgment, without committing a disseisin, since to defend does not mean to render [023] without the tenant's consent. But when the tenant consents or a judgment is given, [024] seisin of the thing claimed is at once transferred to the demandant and the tenant may [025] have escambium to the value from the warrantor's property.
Who may vouch a warrantor and on what grounds.
[027] We must also see who may vouch a warrantor and on what grounds. It is clear that [028] everyone who is not forbidden may vouch a warrantor,