The flag consists of the plain cross version of the national flag, with a golden royal crown superimposed in the center of the cross.
After Otto's abdication in 1862, the royal coat of arms was removed, only to be replaced by a simple royal crown in 1863 when the new king, George I, arrived in Greece. A square version of the land flag with St. George in the centre was adopted on 9 April 1864 as the Army's colours. Similar arrangements were made for the royal flags, which featured the coat of arms of the House of Schleswig-Holstein-Sonderburg-Glücksburg on a square version of the national flag. The exact shape and usage of the flags was determined by Royal Decree on 26 September 1867. By a new Royal Decree, on 31 May 1914, the flag with the crown was adopted for use as a state flag by ministries, embassies and civil services, while the sea flag was allowed for use by private citizens.
On 25 March 1924, with the establishment of the Second Hellenic Republic, the crowns were removed from all flags. On 20 February 1930, the national flag's proportions were established at a 2:3 ratio, with the arms of the cross being "one fifth of the flag's width". The land version of the national flag was to be used by ministries, embassies, and in general by all civil and military services, while the sea flag was to be used by naval and merchant vessels, consulates and private citizens. With the restoration of the monarchy by Georgios Kondylis on 10 October 1935, the crown was restored on the flags. The crown was again removed by the military dictatorship in 1967, following the aborted counter-coup and subsequent self-exile of King Constantine II on 13 December. The sea flag was established as the sole national flag in 1969, using a very dark shade of blue, and on 18 August 1970, the flag ratio was changed to 7:12.
After the restoration of democracy in August 1974, the land flag was restored for a while (Law 48/1975 and Presidential Decree 515/1975) until 1978.