The Syrian flag has seen many changes. The colours of the current tri-colour Syrian flag are traditional Pan-Arabic colours; these colours are also be found on the flags of Yemen, Egypt, Sudan, and Iraq. The two green stars across the white band represent Egypt and Syria, the participants in the UAR. The green colour is thought to be the colour of the Fatimids, white the colour of the Ummayids, black the colour of the Abbasids and red the colour of the blood shed by martyrs. Red is also thought to be the colour of the Hashimite dynasty and added following Sharif Hussayn of Hijaz agreeing to join the Arab revolt in 1916.