The continuation and accumulation of magistracies were also forbidden by _plebiscita_ of the year 342 B.C., which enacted that at least ten years must elapse between the tenures of the same magistracy, and that two magistracies should not be held together in the same year.[817] Such legislation was the starting-point for a series of measures known as _leges annales_, which specified the order in which the various magistracies must be held (_certus ordo magistratuum_),[818] the age which qualified for each, the interval which must elapse between the holding of any two, and that which must intervene between the holding of the same, magistracies. In the year 180 B.C. the _lex Villia_, a _plebiscitum_ of a comprehensive character, was passed, which specified the age at which each magistracy might be held;[819] it appears also to have fixed the interval which must elapse between the holding of two patrician magistracies, since from about this period we find the beginning of the rule, which held good in Cicero’s day, that a biennial interval must be observed between the patrician offices in the _gradus honorum_.[820] Finally, Sulla in 81 B.C. re-enacted the rules about the _certus ordo_ and the interval between the same magistracies by declaring that the quaestorship must be held before the praetorship, and the praetorship before the consulate, and that ten years must elapse before the resumption of the same magistracy.[821] The validity of election was dependent on the observance of certain forms, the first of which was concerned with the presiding magistrate. While the tribune alone could be the president at the election of plebeian magistrates, the consuls and praetors created the _magistratus populi_, but, as we have already shown in connexion with the _interregnum_, none but a consul could preside at the consular and praetorian elections.