According to Caskel, "The history of the [Bahila] tribe becomes clear for the first time under Islam." In the 630s, part of the Bahila migrated from Arabia to Syria and to the vicinity of Basra. They formed part of the early Muslim army, and Bahila tribesmen from Syria were part of the Arab garrison in Khurasan. As members of the Qays, the Bahila took part in the revenge-driven battles between the Qays and Yaman coalitions in the years following the rout of the Qays at the Battle of Marj Rahit in 684. A second major exodus of Bahila tribesmen from Arabia occurred in the early to mid-9th century. Around that time, the Bahila's Arabian territories were largely overrun by the Banu Numayr, a sub-tribe of the Banu 'Amir. The Bahila migrants entered the lower Euphrates region, first in the vicinity of al-Hufayr near Basra and from there into the sandy al-Taff tract on the southern border of the Bata'ih marshes. After 837, these Bahila tribesmen settled in the Bata'ih itself, where in 871 they were attacked by Abbasid troops on their way to suppress the Zanj Rebellion. Consequently, the Bahila allied with the Zanj. Afterward nothing is heard of the Bahila.