THE COMITIA TRIBUTA AND THE RISE OF POPULAR SOVEREIGNTY TO THE YEAR 449 In the belief of the Romans the tribunes of the plebs, originally two, were instituted in 494 as a concession to the seceding commons to win them back to the state.[1583] The historical truth of the first secession need not be discussed here; but there is no good ground for rejecting the view of the ancients either that the tribunate of the plebs owed its existence to a revolution or that it began at as early a date. According to our sources the plebeian tribunes, hence we may infer also the aediles, were for a time elected, and other business affecting the interests of the common people was transacted, in comitia curiata composed potentially of all the citizens.[1584] The change in the form of organization in 471, from curiate to tribal, will be considered below. The president of the comitia which elected the first plebeian tribunes was necessarily a patrician magistrate,[1585] probably the pontifex maximus;[1586] thereafter, with the exception of the comitia for the election of the first plebeian officials after the overthrow of the decemvirs, tribunes of the plebs presided not only for elections but also for judicial business and for the enactment of plebiscites (plebi scita). The object of the office of tribune was the protection of individual citizens, plebeian and patrician alike,[1587] from oppression; and the means was the auxilium (official aid),[1588] which could be rendered in no other way than by personal contact; hence the law prohibiting a tribune from being absent over night from the city[1589] and requiring him to leave the door of his house open during the night.[1590] In the further interest of the citizens the tribunes had the unrestricted right to call the plebs to a contio and address them at any time and on any subject, to form them when so assembled into voting groups, at first curiae and after 471, tribes, and to take their votes on proposals affecting plebeian interests, plebiscites being from the beginning binding on the plebeian body in so far as they harmonized with the laws of the state.[1591]