 Depicted in the mosaic Map of Madaba of 600 , Gaza was the most important political and commercial center on the southern coast of Palestine . Its northern municipal border was marked by Wadi al @-@ Hesi , just before Ashkelon , and its southern boundary is unknown , but Gaza 's jurisdiction did not reach Raphia . The towns of Bethelea , Asalea , Gerarit and Kissufim were included in Gaza 's territories . Its large representation , approximately half of which is preserved , cannot be easily explained , mainly because only small tentative excavations have been made there and because Byzantine Gaza is covered by the still inhabited Old City . 
