So Julius caeser is saved from assassination by being tipped off to it in the nick of time. After realizing he could have almost died he decides to have some I've survived sex with his wife. This gets his 31 year old wife pregnant. And nine months later a son is born that will grow up to be more brilliant then his father but also one of the most argoent men who ever lived.
While the sons growing up his fathers away conquering Parthia west of the zargos and dacia. After those conquest are done he put up his sword and sends out younger men to do the military work for him while he rules rome and raises his son. He dies just after his son turns 25.
This son desires to give Rome an empire like that of Trajan that includes Arabia, the rest of the british isles, Berber and garmante territory, Nubia, Scandinavia, and Europe to the Vistula and Dniester. Can he do it if given suffient power? And what would his position be after his fathers death?