In the Greek Empire, blood spilled in battle is considered sacred.
Date: 500s BCE
According to the Greeks, it is forbidden to spill blood within cities. Blood is seen as a symbol of strength and the place where purity lives; to spill it is seen as dangerous and wasteful, unless it happens within battle. Sacrifice in battle, in which a person's blood is spilled, is seen as sacred–the ultimate sign of bravery and strength.