 By Domitian's time, many had been more or less absorbed by the State, including those at Pergamum, Alexandria, Praeneste and Capua.The city of Rome itself had four; the "Ludus Magnus" (the largest and most important, housing up to about 2,000 gladiators), "Ludus Dacicus", "Ludus Gallicus", and the "Ludus Matutinus", which trained "bestiarii".In the Imperial era, volunteers required a magistrate's permission to join a school as "auctorati".