1Their power is this: once a cause (one or several) is committed to them, though it  is committed simply, their jurisdiction is extended to all matters necessary to  determine the suit,2 so far as judgment and the execution of judgment are concerned,  and so if there is an incidental or emergent action preliminary to it. 3[But]  they cannot extend their jurisdiction to other things or other persons, nor take  cognisance of things other than those comprised in their commission, since the  limits of a mandate must be strictly observed.4
In what way and when their power and jurisdiction may be determined.
 Although some judges are permanent, it is evident that 5their jurisdiction may  nevertheless be ended in many ways, for example, by the death of him who  delegated, or the death of him to whom the cause was delegated, personally and by  name. And so if the principal revokes the jurisdiction or gives it to another judge,  the thing as a whole or part of it. Or if the delegate remits the cause to his  principal6 or to another delegate, for some reason, [for example], because of the day  and place. 7And so when sentence has been given and execution ordered,8 for a  judge by rendering judgment is discharged of his office9 and the jurors freed from  their oath, unless one says that though judgment has been rendered a judge may  nonetheless recall the jurors to certify10 or to inquire into a false oath, [provided  that] he is a major justice or a justice in eyre appointed generally to hear all  pleas.11 In truth, 12once judgment has been rendered in the proper way the judge  who rendered it cannot thereafter change or modify it, though on the same day on  which it was rendered he may make it effective in matters which concern its consequences.13  But this last applies only to those who have been appointed justices  for the taking of assises specially, one, two or several. And finally, note that no  justice so delegated by the king may subdelegate another to himself.14
How justices to travel from county to county generally ad omnia placita or to hear pleas of a particular kind are to be appointed.
 Let us for the present pass over in silence the major justices and those sitting in the  bench.15 We must see how justices to travel from county to county for the hearing  of all causes generally are to be appointed, [or for the hearing of certain kinds of  causes, or of particular causes, one, two or several,]16and then how, after having  taken their oath,17 they ought to conduct themselves in their eyre.18 [First] let a  special writ be drawn for each of them individually
1-2. Tancred, 96-7; Richardson in Traditio, vi, 67