The extensive campaigning abroad by Rome, and the rewarding of soldiers with plunder from those campaigns, led to the trend of soldiers becoming increasingly loyal to their commanders rather than to the state, and a willingness to follow their generals in battle against the state. Rome was plagued by several slave uprisings during this period, in part because in the past century vast tracts of land had been given to veterans who farmed by use of slaves and who came to greatly outnumber their Roman masters. In the last century BC, at least twelve civil wars and rebellions occurred. This pattern did not break until Octavian (later "Caesar Augustus") ended it by becoming a successful challenger to the Senate's authority, and was made "princeps" (emperor).