Trade and warfare helped spread Muslim beliefs beyond Arabia. In turn, Arabs learned more about the different beliefs and lifestyles of the people they conquered.
In many places, the people changed their religion to Islam. They also took up other parts of Arabic culture, especially the language. Sometimes, Arabs started following the customs of people they ruled.
This blending of traditions changed Islam. It became a religion of many cultures. However, Muslims stayed united by their language and faith. Islamic rulers banned many religions. But Christians and Jews were allowed to keep their religions – as long as they paid a tax. Arab Muslims expanded their influence until the 1100s. After that, three non-Arab Muslim groups built powerful empires. These empires ruled parts of Asia, Africa, and Europe. The first of these groups was the Ottomans.