King Alexander

The second-born son of King Constantine I, was born on 1 August 1893 at Tatoi and reigned from 1917, when his father and elder brother - later King George II of Greece - were forced into exile, until 25 October 1920 when he died from gangrene acquired as the result of a monkey's bite. His reign coincided with the Greek occupation of Asia Minor following the first World War. He was married in Athens, in total secrecy, to Aspasia Manou (1896 - 1972), a commoner. Their only child, Alexandra of Greece, was born after his death. She later married King Peter II of Yugoslavia.

|- style="text-align: center;" | width="30%" |Preceded by:
King Constantine I | width="40%" style="text-align: center;" |King of the Hellenes
1917–1920 | width="30%" |Succeeded by:
King Constantine I