Flag of Greece Additionally, the flag may also be flown on days of national mourning, half-mast. The Minister of the Interior has the authority to proclaim flag days if they are not already proclaimed, and proclaiming regional flag days is vested with the elected head of each regional unit (formerly prefectures). Although 17 November is not an official national holiday, Presidential Decree 201/1998 states that respects are to be paid to the flag on that particular day. The War flag (equivalent to regimental colours) of the Army and the Air Force is of square shape, with a white cross on blue background. On
Flag of the Greek Orthodox Church of the Byzantine Empire. The double-headed eagle was historically used as an emblem in the late Byzantine period (14th–15th centuries), but not on flags; rather it was embroidered on imperial clothing and accoutrements by both the Palaiologos emperors of the Byzantine Empire and the Grand Komnenos rulers of the Empire of Trebizond, descendants of the Byzantine imperial family of the same name. The actual flag of the Palaiologan-era Byzantine Empire was based on the tetragrammatic cross in gold on a red background. This design also forms the basis for another flag used by the Orthodox Church of Greece, with the