(1845–1913) reigned 1863–1913. He was born a prince of Denmark, the second son of King Christian IX. After Otto I was overthrown in 1862, the Greek parliament invited Prince William to become king. He took the name George and reigned as a constitutional monarch. George was assassinated during the First Balkan War and was succeeded by his son, Constantine I.

(1890–1947) reigned 1922–23 and 1935–47. He was the eldest son of Constantine I, whom he succeeded as king in 1922. The next year, however, he was deposed, and a republic was declared soon after. In 1935 George was restored to the throne and General Joannes Metaxas was given dictatorial powers. Germany invaded Greece in 1941, and George fled in a British warship. He was restored by a plebiscite in 1946, but soon died.