Since the Old Kingdom, Elephantine, the Nile island opposite Aswan, was the capital of the first nome of Upper Egypt and with its huge temple of the ramb god Chnum (1500 sqm) it was additionally the main religious center of the region. Around the 3rd cent. BC the dominant position of Elephantine began to deteriorate.
On the close island of Philae the newly built Temple of Isis began gradually to take over its religious significance and around the same time, Elephantine lost its administrative position to Omboi, which became the nome capital of what was then called the Ombite nome.
In the course of the Greco-Roman period, Elephantine was replaced as most significant town in the region by Aswan, Roman Syene, that alongside with Philae gained a bishop see not later than the 330s. Nonetheless, Elephantine seems to have maintained a kind of special status, what is indicated by an inscription mentioning a stratēgos Ombitou Elephantinēs in the middle of the 3rd cent. CE (W.Chr. 73 = CIG 5069).