The spread of Islam began with Muhammad. He began to share the revelation which he believed in God (Allah). Muslims conquests after Muhammad's death helped the spread of Islam. These early conquests, coupled with Muslim economics and trading and the later conquests of the Ottoman Empire, resulted in Islam's spread outwards from Mecca towards both the Atlantic and Pacific Oceans and the creation of a Muslim world. The people of the Islamic world created numerous sophisticated centers of culture and science with far-reaching mercantile networks, travelers, scientists, hunters, mathematicians, doctors and philosophers, all contributing to the Golden Age of Islam.