 This system consisted of noble families of the senatorial rank, the knight or equestrian class, citizens (grouped into two or three classes depending on the time period - self-governing allies of Rome, landowners, and plebs or tenant freemen), non-citizens who lived outside of southwestern Italy, and at the bottom, slaves.By law, only men who were citizens could vote in certain assemblies, and only those men who owned a certain amount of real property could serve in the military, which would gain them social prestige and additional benefits of citizenship.The government owned large tracts of farmland ("ager publicus") that it had gained through conquest or escheat (acquisition from owners who had died without heirs); this it rented out to large landholders who used their slaves to till it or who sub-leased it to small tenant farmers.