In the ancient times, it was not uncommon that every able citizen of a city took up arms in case of grave danger. In more peaceful times and countries, this practice was forgotten. One of the reasons why relatively small barbarian hordes succeeded in conquering late Roman cities was that general population of those cities lacked the resolve to defend their homes. Sometimes civilians or slaves were also used in combat unwillingly, especially during sieges; they were forced by club and whip to throw their bodies at the oppossing army, who sometimes were their own comrades.