Among the lowest ranking magistrates in both the early Republic and Roman Empire was the quaestor - “the man who asks questions.” Although the original position (quaestores parracidii) first appeared under the rule of the kings as a prosecutor of murder cases or police inspector, the office came into prominence during the young Republic around 509 BCE when the two consuls (appointing one each) placed quaestores aerarii in control of the public treasury or aerarium. Under the Law of the Twelve Tables, around 450 BCE, when plebians became eligible for the office, their number was increased to four, and with that, the position became a widely sought after job by many young, ambitious men. After 440 BCE they were no longer appointed by the consuls and were, instead, chosen by the assembly.
As new cities and territories came under the control of the empire - especially when Sicily, Corsica, and Sardinia were acquired after the First Punic War against Carthage - the number of quaestors had to be increased. As with their number, their official function changed over the years. Initially, they were only in charge of the treasury; however, their newly expanded duties included collecting taxes and tributes from the territories as well as recruiting new soldiers for service in the army. Eventually, each provincial governor would have his own quaestor.
As new quaestors were added - twenty under Sulla and forty under Julius Caesar (even Caesar had once served as a quaestor) - they were stationed in various cities throughout the empire, gradually acquiring additional functions such as serving as paymasters and occasionally even as military commanders. Likewise, as the empire grew, the qualifications to hold office also changed. Originally, a quaestor had to have at least ten years experience in the army and be thirty years old. Emperor Augustus, while returning their number to twenty, lowered this age requirement to twenty-five and transferred their election to the Senate. In the late second century BCE it had become customary for an ex-quaestor to enter the Senate and Sulla made this appointment automatic. Augustus continued this practice, however, the position became increasingly more ceremonial and a quaestor evolved into nothing more than a messenger for the emperor. Although Claudius temporarily restored the position's financial responsibilities, Emperor Nero reduced the quaestor to a supervisor of the Games - a position held by other government officials including aediles and praetors. Near the end of the Empire, it became more honourary than official and a position sought after by men of wealth. Under Constantine I and the Byzantine emperor Justinian, their value did increase again, becoming legal counsels.