The Battle of Poitiers aka the Battle of Tours took place over roughly a week in early October of 732. The opposing sides consisted of a Frankish army led by Charles Martel (r. 718-741) against an invading Muslim army under the nominal sovereignty of the Umayyad Caliphate (c. 661-750) based in Damascus, Syria.
These two forces came together as Umayyad power sought expansion and plunder in European lands, while Frankish lords sought to defend and consolidate hold over their territory. Some have argued that this brief conflict influenced the fate of Christian civilization in Europe, while others see it as a simple border skirmish. The truth, it seems, lies somewhere in-between.
Though resulting in a Frankish victory, it was not simply Frankish power or the Battle of Tours alone which ultimately halted Umayyad expansion into Western Europe. Internal division within the Umayyad Caliphate itself, affecting its ability to wage war in the region was a major factor. In a broader context, Tours was not a determinant confrontation between the two sides, nor did it effectively deter or immediately diminish Umayyad strength in the region. Rather, the significance of Tours can be found in the circumstances occurring in the wake of Charles’s quick victory over Umayyad power.
https://www.worldhistory.org/article/1809/the-legacy-of-charles-martel--the-battle-of-tours/
Umayyad Dynasty
The Umayyad Dynasty (661-750 CE), the first dynasty to take the title of Caliphate, was established in 661 CE by Muawiya (l. c. 602-680 CE), who had served as the governor of Syria under the Rashidun Caliphate, after the death of the fourth caliph, Ali in 661 CE. The Umayyads ruled effectively and firmly established the political authority of the Caliphate, rebellions were crushed with brute force, and no quarter was given to those who stirred uprisings.
They ruled over a large empire, to which they added vast newly conquered areas such as that of North Africa (beyond Egypt), Spain, Transoxiana, parts of the Indian subcontinent, and multiple islands in the Mediterranean (but most of these were lost). Although the empire was at its ever largest size during their reign, internal divisions and civil wars weakened their hold over it, and in 750 CE, they were overthrown by the Abbasids (r. 750-1258 CE, a rival Arab faction who claimed to be descended from the Prophet's uncle Abbas).
Prelude
After the death of the Islamic Prophet Muhammad (l. 570-632 CE), Abu Bakr (r. 632-634 CE, a senior companion of the Prophet) took the title of the Caliph, hence forming the basis of the Islamic Caliphates (intermittently: 632-1924 CE). Abu Bakr was the first of the four initial caliphs referred collectively by the mainstream Sunni Muslims as the Rashidun Caliphs, while the Shia Muslims only consider the fourth one of these, Ali (a close companion and son-in-law of the Prophet), the sole legitimate candidate for the Caliphate.
In the Rashidun period, the armies of Islam launched full-scale invasions into Syria, the Levant, Egypt, parts of North Africa, the islands of the Greek archipelago, and the whole of the Sassanian Empire. These conquests were initiated by Abu Bakr and successfully carried on by his successors Umar (r. 634-644 CE) and Uthman (r. 644-656 CE). Uthman, however, was not a strong ruler and was murdered in his own house by rebels in 656 CE. His death marked the breaking point in the history of the Islamic empire: his successor Ali (r. 656-661 CE) was pinned between handling a disintegrating realm and people insisting that justice be served to his dead predecessor.
https://www.worldhistory.org/Umayyad_Dynasty/