Encyclopædia Britannica, Ninth Edition/Decurio

DECURIO, an officer in the Roman cavalry, commanding a decuria, which was a body consisting of ten men. There were certain provincial magistrates called decuriones municipales, who had the same position and powers in free and corporate towns as the senate had in Rome. As the name implies, they consisted at first of ten, but in later times the number was often as many as a hundred; their duty was to watch over the interests of their fellow-citizens, and to increase the revenues of the commonwealth. Their court was called curia decurionum, and minor senatits; and their decrees, called decreta decurionum, were marked with D. D. at the top. They generally styled themselves civitatum patres curiales, and honorati inunicipiorum senatores. They were elected with the same ceremonies as the Roman senators, and they required to be at least twenty-five years of age, and to be possessed of a certain fixed income. The election took place on the kalends of March.