Cæsar

Cæsar, name of an old Roman family claiming descent from the Trojan Æneas, which the emperors of Rome from Augustus to Nero of right inherited, though the title was applied to succeeding emperors and to the heirs-apparent of the Western and the Eastern Empires; it survives in the titles of the Kaiser of Germany and the Czar of Russia.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)