Help identifying a painting?

[lea27]

The painting is in a Classical style with landscape, in forefront is I think Mars but its actually another historical character portraying himself as Mars. In the background are other members of the persons family also shown as Gods. I have seen it somewhere in my studies before and its bugging me that I cant remember what it is.

If it helps Alex Reid has been wearing the picture on a t-shirt in the Big Brother house yeaterday!