Before the advent of Islam. It has been said in the hadith: "The Prophet has prohibited us from mutilating the corpses of the enemies" (al- Bukhari; AbC Dawud).

Islam has categorically prohibited its followers from disgracing or
mutilating the corpses of their enemies as was practised in Arabia
before the advent of Islam. It has been said in the hadith: "The Prophet
has prohibited us from mutilating the corpses of the enemies" (al-
Bukhari; AbC Dawud). The occasion on which this order was given is
highly instructive. In the Battle of Uhud the disbelievers mutilated the
bodies of the Muslims, who had fallen on the battlefield and sacrificed
their lives for the sake of Islam, by cutting off their ears and noses, and
threading them together to put round their necks as trophies of war.
The abdomen of Hamzah, the uncle of the Prophet, was ripped open by ...more

Chapter 4: RIGHTS OF ENEMIES AT WAR - Islam 101