Cleopatra's Daughter by Michelle Moran
At the dawn of the Roman Empire, when tyranny ruled, a daughter of Egypt and a son of Rome found each other...Selene's parents are gone, her country has been taken from her and she has been brought to the city of Rome in chains, with only her twin brother, Alexander, to remind her of home and all she once had. Paraded as captives and brought to live among the ruling family, Selene and her brother attend lessons, learning how to be Roman and where allegiances lie. Devoting herself to her artistic skill and training as an architect, she tries to make herself useful, in hope of staying alive and being allowed to return to Egypt. But before long, she is distracted by the young and handsome heir to the empire. But all is not well in the city and when the elusive 'Red Eagle' starts calling for the end of slavery, causing riots and murder, and the Roman army goes to war, Selene and Alexander, the children of Mark Antony, Rome's lost son and greatest rival, find their lives in grave danger.