The Umayyad dynasty was the first major Islamic caliphate, ruling from 661 to 750 CE. It was established after the death of the Prophet Muhammad and the subsequent period of the Rightly Guided Caliphs. The Umayyads expanded the Islamic empire significantly, stretching from Spain in the west to India in the east, and they established their capital in Damascus. The Umayyad dynasty is known for its administrative innovations and the promotion of Arabic as the official language of the empire. They also built impressive architectural structures, including the Dome of the Rock in Jerusalem. However, their rule faced criticism for perceived secularism and favoritism, leading to their eventual downfall by the Abbasid revolution.