The Monarchy of Greece was the country's system of government in which the hereditary monarch was the supreme ruler from 1832 to 1924 and then from 1935 to 1973.

The Monarchy in Greece was appointed by the Great Powers of England, France and Russia, based on the agreements of the London Protocol of 1830. For the office of the monarch, the contracting countries chose Prince Leopold of Saxony-Coburg and Gotha, who did not accept the position. Leopold, in his rejection, invoked, among other things, the opposition in Greece, since the choice had been made by foreign powers. Thus the three powers ended up with Otto.

Otto (1 June 1815 - 26 July 1867), was a Bavarian prince from the House of Wittelsbach who became the first king of the modern Greek state. Some historians report that Otto loved Greece more than anything else, but not the Greeks. He died in Bamberg on July 26, 1867. He wanted to be buried wearing the traditional Greek costume.

George I, King of the Greeks, as his constitutional title was (24 December 1845 - 18 March 1913), was the longest living king of Greece. He was the second king of modern Greece after Otto and leader of the new Royal House. He ascended the throne in November 1863. He was assassinated in Thessaloniki on 18 March 1913.

Konstantinos I (2 August 1868 - 11 January 1923) was king of Greece from 1913 to 1922.

His name is associated with critical periods in modern Greek history, such as the Greek-Turkish War of 1897, the Balkan Wars, and the Asia Minor Catastrophe.

Alexander (August 1, 1893 - October 12, 1920) was King of the Greeks from June 12, 1917, to October 12, 1920. He was the second son of King Konstantinos I and Queen Sophia, was born on August 1, 1893, and died on October 25, 1920. He studied at the Military Academy of Greece, where he graduated in 1912. He participated as an artillery officer in the Balkan Wars.

George II, King of the Greeks (19 July 1890 - 1 April 1947) was King of Greece during the periods 1922-24, 1935-1941 and 1946-1947 and Prime Minister from 19 to 22 April 1941. After the Asia Minor Catastrophe, the movement of 11 September 1922 and the resignation of Konstantinos, he succeeded to the throne as King of the Greeks on 27 September 1922. After a year, he was forced to leave Greece by the Revolutionary Government. Upon his return to the country, George and Ioannis Metaxas laid the groundwork for the country to prepare for the war that was obviously coming.

Paul I of Greece (Athens, December 14, 1901 - March 6, 1964) was King of Greece from 1947 until his death in 1964. Paul was born on December 14, 1901, at the Royal Palace of Tatoi. He was the fourth child of the then Successor Konstantinos and his wife Princess Sophia. In 1916, while World War I had broken out, he began studying at Naval Military School, but the following year (1917) he was forced into exile in Switzerland, along with his father King Constantine and other members of the Royal Family as a demand of England and France. On 19 December 1920, Pavlos returned to Greece with his family and continued his studies at the Naval Military School, graduating in June 1922 with the rank of ensign. As a new officer, he was stationed on the cruiser "Elli".

Constantine II (2 June 1940, Athens) was King of the Greeks from 1964 to 1973, when a referendum abolished the monarchy and the dynasty was deposed by the Junta of the Colonels. He finally resigned from office in Greece with the 1974 referendum, as the citizens chose Republic with no king as the form of government with a percentage of 69.2%.