Ares
Mature Ares on Brettian League sextans
God of war and "sacker of cities", the son of Zeus and Hera, lover of Aphrodite. His notion of war is savage, and he had a penchant for participating in mortals' clashes, like the Trojan War depicted in the Iliad, where he even treacherously switches sides. Of all other deities, he is most at odds with Athena - also a warrior, but one whose perception of combat is different and mitigated by her fondness of wisdom and art. Ares is usually depicted helmeted, naked, and with the standard martial attributes - a shield, spear and trophy.
In the Roman pantheon he came to be known as Mars, and it is in this form that the English-speaking and other Latin-based world is mostly acquainted with him. Thus we have martial arts, martial law and other derivations... The reddish hue of our neighboring planet reminded ancients of the god's sanguineous proclivities and consequently named it after him. It is not clear if this explains why - ever since H. G. Wells' "War of the Worlds" - hypothetical Martians seem to have an aggressive attitude towards earthlings... It is interesting to note that in 1st century BC Rome, the term referred not to outer space aliens, but to terrestrial (Roman, in fact) members of the Marsic Confederation - albeit engaged in the Social War, and thus definitely worthy of the name. Curiosly again, modern Greek retains its own Ares designation for the planet, although association with the name is probably in current practice less related to extraterrestrials than to fans of the prominent eponymous sports club from Thessaloniki. At least, in this respect Ares appears to have a sole distinction among the Olympic gods...
Search for coins with miscellaneous Ares representations.