Many early Muslims were engaged in trade and for this reason they traveled to distant lands in connection with their businesses. Islam reached East and West Africa as well as East Asia and Europe through the travels of Muslim business people.
Islam encourages work in general, and trade and commerce in particular. Prophet Muhammad ﷺ was himself engaged in this profession before he became a prophet. He was a successful businessman known for his integrity. It was for this reason he was honored with the nickname Al-Amin, the Trustworthy.
Trade has always been closely associated with Islam and its growth. The city of Mecca and its people especially the Quraysh tribe were always associated with commerce. Many Meccan business people had commercial connections extending to Abyssinia (Ethiopia) and Syria. According to the Sirah (history) of the Prophet Muhammad ﷺ, the Prophet went on several business expeditions in the Arabian Peninsula well before he received revelations from Allah.
By the death of the Prophet Muhammad ﷺ and the passing of the first generation of his companions, Islam had virtually spread through most of the Arabian peninsula. The generations of Muslims that followed later used their influence and power to develop trade networks even beyond the peninsula. Slowly, Islam was spread through commerce to many far away locations and not through the sword.
It was mostly expansion through trade and not conquest that led to the spread of Islam to many places in Africa, parts of Europe, Asia and beyond. Both small territories and large regions converted to Islam due to contacts with traveling Muslim traders.
In the case where a trade route was over land, merchants traveled in large groups called caravans. Caravans were almost like traveling cities that included everything from doctors and entertainers to armed guards and translators. The armed guards provided protection for the merchants and their goods. A typical caravan would travel around 15 miles a day and would stop at night at rest stops called caravanserai.
The expanse of Islamic trade had a direct result on the spread of the Islamic religion. Traders brought their religion to West Africa where Islam quickly spread throughout the region. People in the far east such as Malaysia and Indonesia also became Muslim through traders and Islamic Sufis (mystics). Over time, large Muslim populations grew in other regions including India, China, and Spain.
The vast expanse of Islamic trade allowed for the cultural exchange of art, science, food and clothing throughout Asia, Africa, and Europe. Muslim merchants were guided by Qur’anic principles that championed fair dealings with one another especially in trade and the prohibition of charging interest on loans. For this reason, Muslim merchants were well respected wherever they went. The humble and honest dealings of the merchants inspired many to embrace Islam, the religion of the merchants.