 Camel caravans, said to have first been used by Muhammad's great-grandfather, were a major part of Mecca's bustling economy.Alliances were struck between the merchants in Mecca and the local nomadic tribes, who would bring goods – leather, livestock, and metals mined in the local mountains – to Mecca to be loaded on the caravans and carried to cities in Shaam and Iraq.Historical accounts also provide some indication that goods from other continents may also have flowed through Mecca.