I was my understanding that while Egypt was a Roman province beginning with Augustus Caesar, that it was considered the personal property of the Emperor. Due to the yearly flooding of the Nile, Egypt was the bread basket of the Roman world, just as it was millenia earlier when the Hebrew Abraham visited. To keep the citizens of Rome fed, the Emperor needed to control the grain supply of the Empire.

While Cleopatra and the Ptolemies reigned, just as under previous pharaohs, the land belonged to Pharaoh under a type of feudal system. Except Pharaoh was more than just the king of Egypt, Pharaoh was the god Horus incarnate. Cleopatra saw herself as the incarnation of the goddess Isis. This continued with the deified Roman Emperors until Christianity replaced paganism in the Fourth Century A.D.