The fact that this principle of the appellate jurisdiction of the Senate required restatement in 54 A.D. prepares us for the ultimate neglect into which it fell. It is certain that by the close of the second and beginning of the third century, Caesar, or his great delegate the praefect of the praetorian guard, is the universal court of appeal for the whole provincial world. This result cannot be attached to any power possessed by the Princeps over the proconsuls of the public provinces; for the statement that he possessed _maius imperium_ over such governors[1834] can only mean that in any collision of authority the Princeps is not inferior to the proconsul. The world-wide appellate jurisdiction of the Princeps was a thing of very gradual growth, and it originated, not from any idea of his prerogative, but from the irresistible tendency of provincial governors, senatorial as well as imperial, to refer their difficulties to the highest interpreting authority in the Roman world, the Princeps and his _consilium_ of judicial advisers. It is no wonder that the man who became the central source of law should also become the universal authority for its interpretation in detail. When we turn to criminal jurisdiction, we find that here too there are three sources of _jus_. The Republic is represented by the _quaestiones perpetuae_ with their praetors and equestrian _judices_, and also by the new criminal jurisdiction which has been attached to the consuls and the Senate; the Principate is represented by the jurisdiction of the Princeps and his delegates. The jurisdiction of the _quaestiones_, so long as it continued,[1835] proceeded on the old lines. They judged except where the case, through a request of the parties accepted by a higher court, was exempted from their jurisdiction. The higher courts, which might stop their jurisdiction by accepting a case, were those of the Senate and the Princeps. Both of these were high courts of voluntary jurisdiction, and no appeal was permitted from one to the other.[1836] Voluntary jurisdiction is by its nature difficult to define; but custom tended to limit the Senate’s cognisance to certain classes of cases. These classes were determined either by the position of the accused or the nature of the offence. The Senate tried ordinary crimes, such as murder, adultery, incest, when they were committed by the members of the upper classes in society,[1837] and there was a growing feeling, which subsequently obtained something like legal recognition, that a senator should be tried by his peers.[1838] But the character of the offence was the chief determinant of the Senate’s jurisdiction. Any offence of a directly political character, even in the early Principate a breach of a treaty by a foreign prince,[1839] tended to come before it. It was the usual court for extortion or other misuse of powers by provincial governors;[1840] it judged offences against the majesty of the state;[1841] and when the