Original sentence: Alexander is styled Crown Prince of Serbia by royalists and some media because when he was born his father was still legally on the throne, albeit in exile, but it is a courtesy title, not a constitutional office, given Serbia is today a republic.He is the son of Peter II, the last king of Yugoslavia, who was from the Karadjordjevic dynasty.July 17, 1945),  born the Crown Prince of Yugoslavia is the current pretender to the throne of Serbia.When Alexander was born the King had already been in exile for over three years, driven out by the Nazi invasion, and he wasn't recognised by any significant political element in Yugoslavia (Tito's Partisans, the Soviets or the Nazi puppet governments), although was head of the legitimate Yugoslavian Government in exile
Edited sentence: Alexander is styled Crown Prince of Serbia by royalists and some media, but it is a courtesy title, not a constitutional office, given Serbia is today a republic.He is eldest son of the last king of Yugoslavia, but at the moment of Alexander's birth the king had already been in exile for over three years, driven out by the Nazi invasion, and he wasn't recognised by any significant political element in Yugoslavia (Tito's Partisans, the Soviets or the Nazi puppet governments), although was head of the legitimate Yugoslavian Government in exile.July 17, 1945),  the former Crown Prince of Yugoslavia and pretender to the throne of Serbia is the son of Peter II, the last king of Yugoslavia from the Karadjordjevic dynasty