The Umayyad Empire ended in 750 primarily due to "discontent amongst non-Arab Muslim converts," which weakened the empire. The Umayyads had established a system that favored Arab Muslims over non-Arab converts, leading to widespread dissatisfaction among the latter. This social and political inequality contributed to unrest and rebellion among non-Arab Muslims, such as the Abbasid revolt, which ultimately resulted in the overthrow of the Umayyad caliphate.
The other options provided do not accurately describe the historical context of the Umayyad collapse:
- The Ottomans did not exist during the Umayyad’s fall; they emerged later in history.
- Muhammad's forces had already conquered the Arabian Peninsula well before the Umayyad era, which began after his death.
- The Umayyads did not convert to Christianity; they remained Islamic, but faced criticism from within the Muslim community for their policies.
Thus, the significant factor in the decline of the Umayyad Empire was the internal strife and discontent that stemmed from their governance and treatment of non-Arab Muslims.