The Muslim conquest of the Levant, also known as the Arab conquest of Syria, took place between 634 and 638 CE. It was part of the Arab-Byzantine Wars and followed clashes between Arabs and Byzantines during Muhammad's lifetime, notably the Battle of Muʿtah in 629 CE. The conquest began two years after Muhammad's death under Rashidun Caliphs Abu Bakr and Umar ibn al-Khattab, with Khalid ibn al-Walid playing a pivotal military role. Prior to the Arab invasion, Syria had been under Roman rule for centuries and witnessed invasions by the Sassanid Persians and raids by their Arab allies, the Lakhmids. The region, renamed Palaestina by the Romans, was politically divided and included a diverse population of Aramaic and Greek speakers, as well as Arabs, notably the Christian Ghassanids.

On the eve of the Muslim conquests, the Byzantine Empire was recovering from Roman-Persian Wars and was in the process of rebuilding authority in Syria and Palestine, lost for nearly twenty years. The Arabs, under Abu Bakr, organized a military expedition into Byzantine territory, initiating the first major confrontations. Khalid ibn al-Walid's innovative strategies played a crucial role in overcoming Byzantine defenses. The Muslims' march through the Syrian Desert, an unconventional route, was a key maneuver that outflanked the Byzantine forces.

The initial phase of the conquest saw Muslim forces under different commanders capture various territories in Syria. Key battles included the encounters at Ajnadayn, Yarmouk, and the siege of Damascus, which ultimately fell to the Muslims. The capture of Damascus was significant, marking a decisive turn in the Muslim campaign. Following Damascus, the Muslims continued their advance, securing other major cities and regions. The leadership of Khalid ibn al-Walid was instrumental during these campaigns, especially in his rapid and strategic capture of key locations.

The conquest of northern Syria followed, with significant battles such as the Battle of Hazir and the Siege of Aleppo. Cities like Antioch surrendered to the Muslims, further consolidating their hold on the region. The Byzantine army, weakened and unable to resist effectively, retreated. Emperor Heraclius's departure from Antioch to Constantinople marked a symbolic end to Byzantine authority in Syria. The Muslim forces, led by able commanders like Khalid and Abu Ubaidah, displayed remarkable military skill and strategy throughout the campaign.

The Muslim conquest of the Levant had profound implications. It marked the end of centuries of Roman and Byzantine rule in the region and the establishment of Muslim Arab dominance. This period also saw significant changes in the social, cultural, and religious landscape of the Levant, with the spread of Islam and the Arabic language. The conquest laid the foundation for the Islamic Golden Age and the expansion of Muslim rule into other parts of the world.