Greece’s former King Constantine II, who ruled until the restoration of the republic from 1964 to 1973, died on Tuesday in Athens at the age of 82, Greek public broadcaster ERT reported.

Former Greek King Constantine II (bottom center)Photo: AP / AP / Profimedia

He was the sixth and last monarch of the House of Schleswig-Holstein-Sonderburg-Glücksburg.

The former sovereign, cousin of King Charles III and godfather of Prince William, “died (…) after a stroke,” reports ERT.

According to Greek media, he was hospitalized in Athens last week due to breathing problems.

As a male line descendant of King Christian IX of Denmark, he retained the title of Prince of Denmark, although according to Wikipedia the Greek branch was excluded from inheriting the Danish throne after constitutional changes.

Some of the king’s supporters refer to him as Constantine XIII, in accordance with the idea that the Greek monarchy is the successor of the Byzantine one, and that the kings of Greece should be counted among the successors of the Byzantine emperors.

Konstantin was removed from power on June 1, 1973 by the leader of the military junta, Georgios Papadopoulos, who proclaimed himself president.