Battle of the Masts
The Battle of the Masts (Arabic: مَعْرَكَة ذَات الصَّوَارِي, romanized: Maʿrakat Dhāt al-Ṣawārī) was a naval battle fought in 655 between the Rashidun Caliphate under the command of Abu al-A'war and the Byzantine Empire led by emperor Constans II (r. 641–668). The battle was part of the earliest campaign by Mu'awiya, the governor of Syria, to reach Constantinople and is considered to be "the first decisive conflict of Islam on the deep".