Flag of Darfur

Sudan

Use	National flag, civil and state ensign
Proportion	1:2
Adopted	20 May 1970
Design	A horizontal tricolour of red, white, and black; with a green triangle based at the hoist.
Variant flag of Sudan
Use	Naval ensign
Proportion	1:2
Adopted	1970

The flag of Sudan (Arabic: علم السودان‎‎) was adopted on May 20, 1970, and consists of a horizontal red-white-black tricolor, with a green triangle at the hoist. The flag is based on the Arab Liberation Flag shared by Egypt, Iraq, Syria, and Yemen, that uses a subset of the Pan-Arab colors in which green is less significant. Prior to the 1969 military coup of Gaafar Nimeiry, a blue-yellow-green tricolor design was used.

According to World Flags 101:

Red, white, black and green are called the pan-Arab colors and have been historically linked to the Arab people and Islamic religion for centuries. The colors stand for Arab unity and independence. The red stripe represents Sudan's struggle for independence and many other struggles, and the sacrifices of the country's martyrs. The white represents peace, light and optimism. It also represents the White Flag League which was a nationalist group that rose up against colonial rule in 1924. The black represents Sudan; in Arabic 'Sudan' means black. It also represents the black flag of nationalists who fought colonial rule during the Mahdist Revolution, late in 19th century. Green represents Islam, agriculture and the prosperity of the land.

In 1881, at the beginning of the Mahdist War, the Mahdi Muhammad Ahmad appointed Abdallahi ibn Muhammad as one of his four caliphs (Khalifa) and handed him a black flag. Abdallahi used his black flag to recruit Baggara Arabs and other tribes from the west. The other caliphs used differently colored flags. The black horizontal stripe in the current Sudanese flag is a reference to this Mahdist-era black flag.

Between 1899 and 1956, Anglo-Egyptian Sudan was administered jointly as a condominium by Egypt and the United Kingdom. The condominium did not have its own flag; instead the flag of Egypt and the flag of the United Kingdom were always flown together, with the British flag taking precedence.