Complex sentence: He converted to Islam, and joined Muhammad after the Treaty of Hudaybiyyah and participated in various expeditions for him, such as the Battle of Mu'tah, which was the first battle between the Romans and the Muslims.
Split into simpler sentences: He converted to Islam, and joined Muhammad after the Treaty of Hudaybiyyah and participated in various expeditions for him, such as the Battle of Mu'tah. It was the first battle between the Romans and the Muslims.