 Most modern scholars identify it with the site of Avalites mentioned in the 1st-century Greco-Roman travelogue the "Periplus of the Erythraean Sea" and in Ptolemy, although this is disputed.The town evolved into an early Islamic center with the arrival of Muslims shortly after the hegira.By the 9th century, Zeila was the capital of the early Adal Kingdom and Ifat Sultanate in the 13th century, and also a capital for its successor state the Adal Sultanate, it would attain its height of prosperity a few centuries later in the 16th century.