How did the Syrian army become the foundation of Umayyad power?

The Syrian army became the foundation of Umayyad power through the strategic efforts of Muʿāwiyah I, who served as the governor of Syria for 20 years before becoming caliph.1

During his governorship, Muʿāwiyah successfully recruited and trained a large, loyal Arab tribal army. This force was instrumental in several ways:1

• Military Consolidation: Muʿāwiyah utilized this army to repel Byzantine attacks and conduct offensive campaigns, which established his reputation and military strength.1
• Political Leverage: During the first Muslim civil war, this loyal force provided Muʿāwiyah with the military backing necessary to challenge ʿAlī and eventually seize control of the caliphate.12
• Imperial Stability: As caliph, Muʿāwiyah based his government in Damascus, using the Syrian army to maintain order, manage tribal rivalries, and exert control over the empire's expanding provinces.12

By keeping these troops in fighting trim through regular campaigns against the Byzantines, Muʿāwiyah ensured the army remained a reliable instrument of state power, effectively anchoring the Umayyad dynasty in Syria.13