Several years later, in 88 BC, a Roman army was sent to put down an emerging Asian power, king Mithridates of Pontus. The army, however, was defeated. One of Marius' old quaestors, Lucius Cornelius <answer>Sulla</answer>, had been elected consul for the year, and was ordered by the senate to assume command of the war against Mithridates. Marius, a member of the "populares" party, had a tribune revoke <answer>Sulla</answer>'s command of the war against Mithridates. <answer>Sulla</answer>, a member of the aristocratic ("optimates") party, brought his army back to Italy and marched on Rome. <answer>Sulla</answer> was so angry at Marius' tribune that he passed a law intended to permanently weaken the tribunate. He then returned to his war against Mithridates. With <answer>Sulla</answer> gone, the populares under Marius and Lucius Cornelius Cinna soon took control of the city.
Who had successfully passed a law whose sole purpose was to lessen the power of the tribunate?
Sulla