The Palestinian flag is based on the Flag of the Arab Revolt, currently used to represent the Palestinian Arab people and adopted by the Palestinian Authority.
The origins of the flag are the subject of dispute and mythology. In one version, the colours were chosen by the Arab nationalist 'Literary Club' in Istanbul in 1909, based on the words of the thirteenth century Arab poet Safi a-Din al-Hili. Another version credits the Young Arab Society, formed in Paris in 1911. Yet another version is that the flag was designed by Sir Mark Sykes of the British Foreign Office. Whatever the correct story, the flag was used by Sharif Hussein by 1917 at the latest and quickly became regarded as the flag of the Arab national movement.
The flag is constituted of three equal horizontal stripes (black, white and green from top to bottom) overlaid by a red isosceles right triangle issuing from the hoist. The flag is almost identical to that of the Iraqi Baath Party and very similar to the flags of Western Sahara, Sudan and Jordan; all of these draw their ultimate inspiration from the flag of the Arab Revolt against Ottoman rule (1916-1918), which had the same graphic form, but the colours were arranged differently than in the modern flags (white on the bottom rather than in the middle).
Other flags derived from the flag of the Arab revolt include the flags of Jordan, Iraq and the Syria.
On October 18, 1948, the all-Palestine Government adopted the flag of the Arab Revolt in Gaza and the Arab League subsequently recognized it as the flag of the All Palestine Government. A modified version was officially adopted as the flag of the Palestinian people by the Palestine Liberation Organization (PLO) in 1964. On November 15, 1988 the PLO adopted the flag as the flag of the State of Palestine. Today the flag is flown widely by Palestinian Arabs and their supporters.