What ARE the main differences between the Greek Ares, and the Roman Mars?
Well, Ares is… not a popular god, put it that way. In scenes from the Iliad depicting interactions between the gods, he’s consistently treated as something of an outcast, Zeus’ least-favourite child (in stark contrast to perfect daughter Athena). Not a lot of people really worship Ares – he personifies bloodlust, the madness of battle and war. Mars, on the other hand, was originally a god of agriculture in pre-classical Italy before he became a martial god closely identified with Ares, and was one of the foremost patron deities of the Roman state; he stood for martial discipline, justice and vengeance upon the guilty. In a polytheistic society, it’s not uncommon to note a couple of similarities between one of your gods and one worshipped in another neighbouring culture, and decide “eh, it’s probably the same guy,” even if you wind up glossing over a few differences in the process. They’re gods; they can be several mutually contradictory things at once if they want to.