Censors were the most august of all Ancient Roman magistrates. However, the office lacked imperium and as such, censors were not entitled to display fasces or be escorted by lictors.
Censors were elected by the Centuriate Assembly, and the term of office was actually a full five years (called a lustrum) though it is generally accepted that most censorial duties were limited to the first eighteen months of the lustrum.
Each lustrum was welcomed in with a special sacrifice, called the suovetaurilia, of pig, sheep, and ox. No man could stand for the office of censor unless he had first been consul and usually only consulars of notable auctoritas and dignitas ever bothered to run.
In addition to regulating Senate membership, censors were tasked with inspecting and regulating the membership of the Ordo Equester. In their role during the census they had the authority to move a citizen from one tribe to another as well as one Class to another, by applying the means test. They also were responsible for letting State contracts for everything from tax farming to public works.
Sulla abolished the office of censor in 81 B.C., but the consuls Pompey and Crassus reinstated it eleven years later in 70 B.C.
Censors wore a purple toga called the toga purpurea.