According to medieval Arabic sources, prior to their entry into the Oriens, the Salihids had been established in the northern Arabian Peninsula. The medieval Arab historian Umar ibn Shabba reported that as early as the 3rd century, the Salihids had allied with the Palmyrene Empire and were settled by the latter in the manāẓir al-Shām (watchtowers of the Limes Arabicus, the Byzantine-Arabian frontier) between Balqa (central Transjordan) and Huwwarin. Most sources point to an original migration from Wadi Sirhan, a valley whose northern end opened into the Byzantine province of Arabia Petraea. This valley was also home to the Salihids' Quda'a kinsmen, the Banu Kalb, making it more plausible that the Salihids entered Oriens from Wadi Sirhan.