Islam began with the prophet Muhammad, who received revelations from God that were recorded in the Quran. The key beliefs and practices of Islam are articulated in the Five Pillars: the shahadah (declaration of faith), salat (prayer), zakat (charity), sawm (fasting during Ramadan), and hajj (pilgrimage to Mecca). Islam spread rapidly after Muhammad established the first Muslim community in Medina in 610 CE due to the zeal of new converts and because the Islamic armies were able to defeat the weakened Byzantine and Sasanid empires.