For most of human history, depending on the culture of the victors, enemy combatants on the losing side in a battle who had surrendered and been taken as prisoners of war could expect to be either slaughtered or enslaved. Early Roman gladiators could be prisoners of war, categorised according to their ethnic roots as Samnites, Thracians, and Gauls ("Galli"). Homer's "Iliad" describes Greek and Trojan soldiers offering rewards of wealth to opposing forces who have defeated them on the battlefield in exchange for mercy, but their offers are not always accepted; see Lycaon for example.