Answer: constantine

AnswerCrossword Clue
CONSTANTINEGen. ... Rokossovsky.
CONSTANTINEKing of Hellenes, abdicated in 1922.
CONSTANTINEYouthful European monarch.
CONSTANTINEEponym of the city now known as Istanbul
CONSTANTINEImperial convert
CONSTANTINEEmperor who called the First Council of Nicaea