Research questions for a book

[M. Caecilius]

Ok, here's my list of questions.

[...]

I have read that legates have to be patricians, but surely that is not the case since there are legates recorded in history who started out as plebeians.

Patrician status was not essential to be a legate. Take T. Flavius Vespasianus, a member of the gens Flavia, which was plebeian, but he was the legate of II Augusta. So was the gens Petilia, to which Cerialis, legate of IX Hispanica (amongst other) belonged, and the gens Aelia, the family of Hadrian (I Minervia P.F. in 106); all according to Smith's Dictionary. Two of these managed to rise quite a bit higher, too, later in life.

Remember that ever since the end of the Struggle of Orders way back in the childhood days of the Republic, patrician and plebeian status lost quite a bit of impact on public life, except for a few offices barred to one or the other (Tribune of the Plebs, Curule or Plebeian Aedile,...).

If you mean to ask whether one could be a legate without first being a Senator, I think that a legatus had to be praetor first, but that could be remedied by the grant of praetoria insignia (as I understand it, the rank of a praetor without actually having held the office, cf. Tacitus Hist.4.4]. Thus Cornelius Fuscus, an equestrian by birth, led V Alaudae in 69, if I understand correctly without having really entered the cursus honorum or the Senate. Civil Wars do help people overlook constitutional niceties, though.