Battle of Dibba. The plain behind Dibba still contains a large cemetery which according to local tradition represents the fallen apostates of Dibba. Thereafter, the region of southeast Arabia became nearly entirely Muslim. During the time of the Abbasid caliph Al-Mu'tadid (CE 870–892), a great battle was fought at Dibba during the conquest of Oman by the Abbasid governor of Iraq and Bahrain, Muhammad ibn Nur. Thereafter references to Dibba in historical literature are scarce until we come to the Portuguese who built a fortress there. Dibba (Debe) appears in the list of southeast Arabian placenames preserved by the Venetian jeweler Gasparo Balbi in CE 1580 and depictions of its Portuguese fort can be found in several sources, such as Armando Cortesão's Portugaliae Monumenta Cartographica. Portuguese Around 1620–1621 the Italian traveler Pietro Della Valle, while staying with the Sultan of Bandar Abbas, met the son of the ruler of Dibba. From this he learned that Dibba had formerly been subject to the Kingdom of Hormuz, but was at that time loyal to the Safavids. In 1623, Safavids sent troops to Dibba, Khor Fakkan and other ports on the south-east coast of Arabia in order to prepare for a Portuguese counter-attack, following their expulsion from Hormuz (Jarun). The Portuguese, under Rui Freire, were so successful that the people of Dibba turned on their Safavid overlords putting them all to death, whereupon a Portuguese garrison of 50 men was installed at Dibba. More Portuguese forces had to be sent to Dibba in 1627 as a result of an Arab revolt. Two years later the Portuguese proposed moving part of the Mandaean population of southern Iraq to Dibba under pressure from neighboring Arab tribes. Although Dibba was offered to the Mandaeans they were wise enough to see that the Portuguese force there would be insufficient to guarantee their security and, while a few Mandaeans tested the waters by moving to Muscat, most returned to Basra in CE 1630. In 1645 the Portuguese still held Dibba but the Dutch, searching for potential sites for new commercial activities, sent the warship Zeemeeuw ('Seagull') to explore the Musandam peninsula between Khasab, on the Persian Gulf side, and Dibba on the east coast. Claes Speelman, the captain of the Zeemeeuw, made drawings in his logbook, including what is certainly the earliest depiction of Dibba in a European source. Within a year or two the Portuguese were forced