In the late Roman and Byzantine periods, the town extended over the ancient tell (archaeological mound), across the broad central valley of the town today known as the Wadi al-Jirm (see photograph), and over the slopes and summit of the southern hill known as Tell al-Husn. By the Byzantine era, Pella had reached its maximum size and, probably, prosperity. Being part of the province of Palaestina Secunda ("second Palestine"), it certainly had a bishop by the year AD 451. At least three triapsidal churches have been identified within the city: the West Church at the western foot of the tell; the Civic Complex church in the Wadi al-Jirm at the southeast foot of the tell and which, due to its size and location, was probably the cathedral; and the elevated East Church on the higher slopes of the Jebel Abu el-Khas. A Bishop's palace from ca. 550 CE was also discovered. On the tell, the entire summit was leveled off and a new gridded urban zone constructed during the time of the Byzantine emperor Justinian I. The access streets were lined with newly built shops and large buildings, serving both commercial and residential functions. This concern with urban development matched similar activities in other Decapolis towns, such as Gadara (Umm Qays) and Gerasa (Jerash/Jarash), and reflects the role of regional centres in serving local populations during late antiquity. Early Islamic period On the plain of the Jordan Valley below Pella, a historically decisive battle took place in January 635 CE (13 AH) between a Muslim army and the Byzantine forces stationed at Pella and Scythopolis (Beit She'an; Beisan). This encounter, one of the earliest between Muslims and Byzantines, came to be known as the Battle of Fihl (also Battle of Fahl, Fahl being a later variant of Fihl). As the Byzantine forces practically annihilated in this battle, the Muslims forces continued to the town of Pella, where they faced little resistance with the town of Pella surrendering by treaty, thereby avoiding occupation by military conquest. Accordingly, the archaeological record shows no disruption attributable to the arrival of Islam, as was the case for nearly all the towns of Bilad al-Sham. Rather, the churches, markets and houses of Pella continued in use, with the archaeology showing their progressive modification to meet evolving social and political conditions, as in many of the other towns of the Decapolis alliance in north Jordan. In