The supporters of Gaius Gracchus who had survived the slaughter and the subsequent assizes held by Opimius, were eager to avenge their leader and friends. By 120 b.c., they had gathered sufficient strength to challenge both the chief persecutor and the implications of the senatus consultum ultimum: Opimius was brought to trial 'apud populum' by a tribune named Decius Subulo. 2 A fundamental question of law was at stake: what latitude might be allowed to a magistrate in the exercise of his imperium at a time of internal disturbance, especially when he was backed by the moral authority of the Senate? Granted that the 'salus populi' must be the 'suprema lex', was he justified in disregarding the ius provocationis which Roman citizens had enjoyed for nearly 400 years, and in putting them to death without trial or appeal? It would seem that if men had actually raised arms against their country, they automatically became hostes and ceased to enjoy the rights of citizens: thus a strong case could be made for Opimius in his suppression of the Gracchans who fought on the Aventine. But it was very different when men had been disarmed or arrested later: many of these had not been granted any form of trial and those who secured the doubtful privilege of being hauled before Opimius' assize had been summarily executed without opportunity to exercise their right of appeal and in defiance of Gracchus' law 'ne quis iniussu populi Romani capite damnetur'. Here Opimius' action must have been illegal, but nevertheless he was acquitted. 3 One of his stoutest supporters at the trial was C. Carbo, who had deserted the Gracchan cause and had been rewarded with the consulship of 120. This renegade even went so far as to claim that Gaius had been justly killed, but in the following year he was 37himself prosecuted on some charge by the young orator L. Crassus and committed suicide. Thus by the acquittal of Opimius the authority of the Senate and its agent was vindicated; it received further backing when the People was persuaded by a tribune, L. Calpurnius Bestia (120, or possibly 121), to recall Popillius Laenas, who had been forced into exile by Gaius Gracchus for the part that he had played in the suppression of the followers of Tiberius (p. 27). 4