Death of the last pagan Roman Emperor, Julian the Apostate, fatally wounded on June 26, 363 AD. SIT TIBI TERRA LEVIS

Funny enough, it's what killed him. Julian rushed off to bolster his men during a surprise attack, but was in such a rush that he didn't put his armor on. For that reason, a Persian soldier managed to impale him with a javelin, and he spent the next three days slowly dying.

Moral of the story - put your damn armor on before battle.