The Sengoku jidai ("warring-states period") was marked by the loosening of samurai culture with people born into other social strata sometimes making names for themselves as warriors and thus becoming de facto samurai. In this turbulent period, bushido ethics became important factors in controlling and maintaining public order.
Japanese war tactics and technologies improved rapidly in the 15th and 16th century. Use of large numbers of infantry called ashigaru ("light-foot", due to their light armor), formed of humble warriors or ordinary people with nagayari (a long lance) or (naginata), was introduced and combined with cavalry in maneuvers. The number of people mobilized in warfare ranged from thousands to hundreds of thousands.