The Early Islamic Expansion refers to the rapid spread of Islam and its territories following the death of the Prophet Muhammad in 632 CE. Within a century, Muslim armies conquered vast regions, including parts of the Byzantine and Sassanian empires, leading to the establishment of a vast Islamic caliphate that stretched from Spain to India. This expansion was driven by a combination of military conquests, trade, and the appeal of Islamic teachings. The Umayyad and Abbasid caliphates played significant roles in this process, facilitating cultural exchanges and the spread of knowledge across diverse regions, which laid the foundation for future Islamic civilization.