Complex sentence: Mu'nis al-Khadim sent forces to assist the beleaguered city, but in the resulting skirmishes, the Byzantines prevailed and took many prisoners and the Arab army returned home without relieving the city.
Split into simpler sentences: Mu'nis al-Khadim sent forces to assist the beleaguered city. In the resulting skirmishes, the Byzantines prevailed and took many prisoners and the Arab army returned home without relieving the city.