The optimates (//; Latin: optimates, "best ones", singular optimas; also known as boni, "good men") were the traditionalist Senatorial majority of the late Roman Republic. They wished to limit the power of the popular assemblies and the Tribunes of the Plebs, and to extend the power of the Senate, which was viewed as more dedicated to the interests of the aristocrats who held the reins of power. In particular, they were concerned with the rise of individual generals who, backed by the tribunate, the assemblies and their own soldiers, could shift power from the Senate and aristocracy. They were opposed by the populares.
Many members of this faction were so classified because they used the backing of the aristocracy and the senate to achieve personal goals, not necessarily because they favored the aristocracy over the lower classes. Similarly, the populares did not necessarily champion the lower classes, but often used their support to achieve personal goals.
Cicero, for example, a strong supporter of the optimates' cause, was himself a novus homo, being the first in his family to enter the Senate; he was thus never fully accepted by the optimates. On the other hand, during the civil war of 49 BC, Julius Caesar, of a respectable old family, contended against a Senate championed by Pompey the Great, from a wealthy but recently-enobled family.
In addition to their political aims, the optimates opposed the extension of Roman citizenship, and sought the preservation of the mos maiorum, the ways of their forefathers. They sought to prevent successful generals, such as Gaius Marius, Pompey the Great, and Julius Caesar, from using their armies to accrue such power that they might be in a position to challenge the Senate. They opposed Marius' plan to enlist impoverished Romans, too poor to provide their own arms and supplies in the legions, and the generals' attempts to settle these veterans on state-owned land.
The optimates' cause reached its peak under the dictatorship (81 BC) of Lucius Cornelius Sulla. Sulla's administration stripped the Assemblies of nearly all power, raised the number of members of the Senate from 300 to 600, executed an equally large number of populares via proscription lists, and settled thousands of soldiers in northern Italy. However, after Sulla's withdrawal from public life (80 BC) and subsequent death (78 BC), many of their policies were gradually reversed.
Besides Sulla, notable optimates included Lucius Licinius Lucullus, Cato, Milo, Bibulus, and Brutus. Though the optimates had opposed him for the entirety of his political career, Pompey the Great also found himself as the leader of the optimates' faction once their civil war with Julius Caesar began in 49 BC. Optimates who (along with disillusioned populares) had carried out Caesar's assassination in 44 BC called themselves Liberatores.
A historian of the Late Republic cautions against understanding the terms populares and optimates as solid factions or as ideological groupings:
|“||Our chief contemporary witnesses to the political life of the late Republic, Cicero and Sallust, are fond of analyzing the political struggles of the period in terms of a distinction between optimates and populares, often appearing with slight variations in terminology, such as Senate, nobility, or boni versus People or plebs. ... The polarity obviously corresponds with the dual sources of institutional power in the Republic — Senate and People…. It is important to realize that references to populares in the plural do not imply a co-ordinated 'party' with a distinctive ideological character, a kind of political grouping for which there is no evidence in Rome, but simply allude to a recognizable, if statistically quite rare, type of senator whose activities are scattered sporadically across late-Republic history … The 'life-long' popularis … was a new and worrying phenomenon at the time of Julius Caesar's consulship of 59: an underlying reason why the man inspired such profound fears.[dead link]||”|
133[:] Tribute of Ti. Gracchus, his 'lex agraria' and destruction by a rabble of optimates, headed by P. Scipio Nasica [...]