‘The sovereign power of the dictator, the imperium, was … an unrestricted regal power, taken over ca. 504 B.C. by the 300 horsemen of the noblemen-bodyguard, who constituted then the patriciate, i.e. the closed circle of the potential holders of the imperium’. This is a quotation from A. Alföldi's latest book, Early Rome and the Latins (Ann Arbor), 1965, p. 44, and summarizes his theory of the origins of the Roman Republic. According to Alföldi the aristocracy of the monarchic period was an aristocracy of knights, and their coup d'état of about 504 B.C. brought about the end of the monarchy. As is well known, Alföldi developed this theory in a previous book, Der frührömische Reiteradel und seine Ehrenabzeichen (Baden-Baden, 1952) which is chiefly meant to prove that the various attributes of the senatorial order—including the special shoe for the patrician senators, the calceus patricius—were originally characteristic of the archaic knights. To the best of my knowledge, Alföldi never says explicitly that the senators of the monarchic period must have been identical with the 300 ‘celeres’ who were the king's bodyguard according to some of the ancient sources (Livy 1, 15, 8; Plut., Rom. 26; Zonaras 7, 3, 4). But this seems to be Alföldi's implication—in fact it was already Niebuhr's hypothesis.