During the Second Muslim Civil War, the Qays tribes of the Jazira backed the Mecca-based opponent of the Syria-based Umayyads, Abd Allah ibn al-Zubayr. They had no special attachment to the Umayyads, whom they resented for opening the Jazira to immigration, and may have hoped that Ibn al-Zubayr would restore their autonomy. The Qays were routed by the Umayyads and their Arab tribal allies, chief among them the Banu Kalb, at the Battle of Marj Rahit near Damascus in 684. A leader of the Qays, Zufar ibn al-Harith al-Kilabi, afterward rallied the tribe's opposition to the Umayyads from the fortified Jaziran town of Qarqisiya (Circesium), located near the confluence of the Euphrates and Khabur rivers. Between about 686 and 689 Zufar and his Qaysi ally Umayr ibn al-Hubab al-Sulami engaged the Kalb in the Palmyrene steppe and the Taghlib and its Rabi'a allies throughout the Jazira in a series of raids and counter-raids, known in the Arabic sources as the "ayyam" ([battle]-days). The Taghlib, whose conflict with the Qays stemmed from the latter's encroachments on their grazing pastures and water sources, were generally bested during these battles, but killed Umayr in 689, while the Kalb were driven out of the Palmyrene steppe where the Qays became the dominant power.