They didn't. Ares came first
The Latin name for Ares, the Greek god of war, is Mars.
mars
The greek name for Mars would be Ares, the god of war and the roman name would again be Mars.
Ares or Mars the Roman name for Ares symbol is a spear for war.
Mars (the Roman God of War) was based on Ares (the Greek God of War).
mars
Ares
Mars
The name Mars comes from the Roman god Mars which in Greek is Ares.
Mars=Ares- god of war
Mars's Greek name was Ares.
The name for Mars is the Roman name of the Greek wars god Ares