The entire Arab society was divided into tribes known as Qabila, headed by a chief. The chief of Qabila (Tribe) was elected on the basis of his family, wisdom and courage. Besides these, his personality also played a crucial role. Each tribe had its own religious beliefs. They worshipped their own gods and goddesses in mosques. The tribes were nomadic, and kept on moving from one region to another in search of food and fodder for their camels. Some of them settled and practised trade or agriculture. Muhammad's own tribe was Qurayash who had reigned its supremacy in Mecca. It established its control over Kaba, a cublic like structure in which idols were placed. Even the tribes outside Mecca considered the Kaba installed their own idols at this shrine, making annual pilgrimage (Hajj) to the shrine.