What effect Byzantine rule over Constantinople as well as the Islamic defeat by Charles Martel in 732 c.e. Have on the spread of Islam?

Byzantine rule over Constantinople provided a significant buffer against the further expansion of Islam into Europe, preserving Christian dominance in the region. The Islamic defeat by Charles Martel at the Battle of Tours in 732 C.E. similarly halted the northward spread of Islamic influence into Western Europe. These events helped solidify the geographic and cultural boundaries between the Islamic world and Christendom, allowing both to develop independently. Consequently, while Islam continued to spread in other regions, its western expansion was effectively curtailed.