27 BC. The constitution of the Roman Republic was a constantly-evolving, unwritten set of guidelines and principles passed down mainly through precedent, by which the government and its politics operated. Senate The senate's ultimate authority derived from the esteem and prestige of the senators. This esteem and prestige was based on both precedent and custom, as well as the caliber and reputation of the senators. The senate passed decrees, which were called senatus consulta. These were officially "advice" from the senate to a magistrate. In practice, however, they were usually followed by the magistrates. The focus of the Roman senate was usually directed towards foreign policy. Though it technically had no official role in the management of military conflict, the senate ultimately was the force that oversaw such affairs. This was due to the senate's explicit power over the state's budget and in military affairs. The power of the senate expanded over time as the power of the legislative assemblies declined, and the senate took a greater role in ordinary law-making. Its members were usually appointed by Roman Censors, who ordinarily selected newly elected magistrates for membership in the senate, making the senate a partially elected body. During times of military emergency, such as the civil wars of the 1st century, this practice became less prevalent, as the Roman Dictator, Triumvir or the senate itself would select its members. Towards the end of the Republic, the senate could enact a senatus consultum ultimum in times of emergency, instead of appointing a dictator. Legislative assemblies The legal status of Roman citizenship was limited and was a vital prerequisite to possessing many important legal rights such as the right to trial and appeal, to marry, to vote, to hold office, to enter binding contracts, and to special tax exemptions. An adult male citizen with the full complement of legal and political rights was called "optimo jure." The optimo jure elected their assemblies, whereupon the assemblies elected magistrates, enacted legislation, presided over trials in capital cases, declared war and peace, and forged or dissolved treaties. There were two types of legislative assemblies. The first was the comitia ("committees"), which were assemblies of all optimo jure. The second was the concilia ("councils"), which were assemblies of specific groups of optimo jure. Citizens were organized on the basis of centuries and tribes, which would each gather into their own assemblies. The Comitia Centuriata ("Centuriate Assembly")