Quæstor (kwěs'tǒr) anciently was the title of a class of Roman magistrates, reaching as far back, according to all accounts, as the period of the kings. The oldest quæstors were the quæstores parricidii (investigators of murder, finally public accusers), who numbered two. Their office was to conduct the trial of persons accused of murder and to execute the sentence that might be pronounced. They ceased to exist as early as 366 B. C., when their duties were transferred to the triumviri capitales. But a far more important though later office was the quæstores classici, to whom was intrusted the charge of the public treasury. They seem to have gained the name of classici from their having been elected originally by the centuries. At first there were only two, but in 421 B. C. two more were added. Shortly after the breaking out of the First Punic War the number was increased to eight; and, as province after province was added to the Roman republic, they amounted in the time of Sulla to twenty and in the time of Cæsar to forty. At first only patricians could be quæstors; but after 421 B. C. the office was open to plebeians also.