The Khawarij were the first Islamic group to emerge after the assassination of Caliph Uthman III, forming the first republican party in the early days of Islam. Their symbol was the red flag. Arab tribes who participated in the conquest of North Africa and Andalusia carried the red flag, which became the symbol of the Islamic rulers of Andalusia (756-1355). In modern times, red symbolizes the Ashrafs of the Hijaz and the Hashemites, descendants of the Prophet. Sharif Hussein designed the current flag as the flag of the Arab Revolt on June 1916. The Palestinian people raised it as the flag of the Arab National movement in 1917. In 1947, the Arab Ba'ath Party interpreted the flag as a symbol of the liberation and unity of the Arab nation. The Palestinian people readopted the flag at the Palestinian conference in Gaza in 1948. The flag was recognized by the Arab League as the flag of the Palestinian people. It was further endorsed by the PLO, the representative of the Palestinians, at the Palestinian conference in Jerusalem in 1964.
The Prophet Mohammad (570-632)
In the seventh century, with the rise of Islam and subsequent liberation of Mecca, two flags - one white, one black - were carried. On the white flag was written, "There is no god but God (Allah) and Mohammad is the Prophet of God."
In pre-Islamic times, the black flag was a sign of revenge. It was the color of the headdress worn when leading troops into battle.
Both black and white flags were placed in the mosque during Friday prayers.
The Abbasid Dynasty (750-1258), ruling from Baghdad, took black as a symbol of mourning for the assassination of relatives of the Prophet and in remembrance of the Battle of Karbala.
The Umayyad Dynasty (661-750), Damascus
The Umayyads ruled for ninety years, taking white as their symbolic color as a reminder of the Prophet's first battle at Badr, and to distinguish themselves from the Abbasids, by using white, rather than black, as their color of mourning.
Mu'awia Ibn Abi Sufian (661-750), founder of the Umayyad state, proclaimed himself Caliph of Jerusalem.
The Fatimid Dynasty (909-1171), North Africa
The Fatimid Dynasty was founded in Morocco by Abdullah Al-Mahdi, and went on rule all of North Africa.
They took green as their color, to symbolize their allegiance to Ali, the Prophet's cousin, who was once wrapped in a green coverlet in place of the Prophet in order to thwart an assassination attempt.
Sources: PASSIA: Palestinian Academic Society for the Study of International Affairs; Evolution of the Arab Flag, by Mahdi Abdul Hadi, Amman, Feb. 1986