Cleopatra is really an amazing historical figure. The Ptolemys only spoke Greek and wouldn’t mix with the conquered Egyptians.
The Egyptian religion allowed the Ptolemys to retain power over centuries, including their linguistic and racial purity. Inbreeding being a common method.
Cleopatra was the first to speak Egyptian and I’d thought that gave her special acknowledgment in their history.
One of the Ptolemies invented a deity, Serapis, which was a hybrid deity designed to appeal to the broadest possible population, and (thanks to overlaps in characteristics and liturgy) cannibalize the devotees of the many gods of the Egyptian pantheon, as well as those of the Greek pantheon, *and* the various peoples of the former conquests of Alexander, i.e. the former Persian Empire — because Ptolemy had designs on ruling the whole thing. Call it a religious reform. :’)
I’m not sure about the racial purity thing. From what I understand, they found the remains of Cleopatra’s full-blooded sister. She was bi-racial. Google “Cleopatra’s sister” for further information. There was a tv documentary from what I remember. Maybe the Ptolemys were essentially Greek at the beginning of the dynasty, but as time went on, they did mate with the locals.
Until Cleopatra, then, none of them would "talk like an Egyptian"..