It's one of the questions I get asked most often: Are the Hellenic and Roman Gods the same deities? I am distinctly not of this opinion. Personally, I think that the Hellenic and Roman deities share the same (Hellenic) base, but that the Roman deities differ from the Hellenic ones. Some not so much, other a great deal.

In general, I regard the Roman Gods as epithets of the Hellenic ones, with a few notable exceptions--especially where there is no viable counterpart in Hellenic mythology. Why? Well, for one, the Theoi came first. The Roman empire came up about a thousand years after the rise of the Theoi.  Hellenic mythology featured the Hellenes, their stories and their cities, while Roman mythology focussed on the Roman people, their stories and their cities. The Hellenes had the Iliad as a major introductory and poetic text to introduce the Theoi, and the Romans had their own text: the Aeneid, a Latin epic poem, written by Virgil between 29 and 19 BC, that tells the legendary story of Aeneas, a Trojan who travelled to Italy, where he became the ancestor of the Romans.

This, obviously, refers to mythology. Societally speaking, the Romans and the Roman Gods didn't "evolve" out of the Hellenic empire. In fact, the barbaric tribes which later went on to conglomerate and form the Roman empire were in the area long before the ancient Hellenes came together as a people. The above is not a societally reflection, it's a mythological one. For more on this, see tomorrow's post.

Differences in the two societies also reflected on the Gods and Their importance. For one, the Hellenes valued  physical prowess, but it were poets and scholars who were held in the highest regards. For Rome, it were the warriors who received the most attention. This reflected in the Gods of both people as well: the Roman Gods resemble the Hellenic Gods, but they are stricter, harder and possess more bloodlust. At the same time, they were also pruder when it came to excesses of any kind. Ares, temperamental God of War, has his Roman counterpart in Mars, yet, Mars is a much stabler God, who is also in charge of agriculture and fertility. Bacchus, the Roman equivalent of Dionysos, lost all ecstatic rites that made the worship of Dionysos so famous.

Another major example of the differences between the two religions was that the Romans had no set shape for their Gods: they looked different to every individual. They were not revered for Their beauty, like their Hellenic counterparts. The Hellenes knew exactly how their Gods looked. They were often described as having muscular bodies (for the men), beautiful eyes and hair (both men and women), and delicate ankles (women). They were role-models to strive towards. Not so for the Romans.

The Roman culture also had a thing for the afterlife. Where the Hellenes focussed on this life and saw death as an inevitable conclusion of it, the Romans struggled to do good deeds and live good lives to be rewarded in the afterlife. They felt that, if they had been good enough, brave enough, warrior-like enough, they would take their place with the Gods after death. The Hellenes worried more about the judgement of the Theoi while they were still alive and knew they would go to the Underworld afterwards. Of course, things changed in that regard already: the mysteries brought the idea of awareness after reincarnation, and parts of the Underworld fell into disuse.

It seems to me, that the Romans tried becoming Gods their whole lives, while the Hellenes accepted their lot as mortals, and respected the Theoi as all-powerful and all-ruling. A frame of mind like that shows in Gods that get neatly packaged, made non-threatening and can be rivalled by mortals. Yet, because of the warrior mentality of the Romans, the Gods that became more predictable and less formed, also became harder. They still punished socially unacceptable behaviour, however, and myths from the Hellenic period got retold from the viewpoint of a warrior's society.