Praetorian Guard
Praetorian Guard, a body of troops in the Roman Empire. Originally it was a guard for the praetor, the military commander at Rome. Under Augustus (ruled 27 B.C.-14 A.D.) it became an imperial guard of 9,000, permanently stationed on the outskirts of Rome. The guardsmen were recruited from Italian volunteers, and enjoyed better pay and shorter service than regular soldiers.
As the only troops near Rome, the Praetorian Guard sometimes made and deposed emperors. In 193 Septimius Severus disbanded the old Guard and recruited a new one from his non-Italian legionnaires. Constantine the Great abolished the Praetorian Guard in 312.