(waterwheel), are still used, unchanged, today. Many place names in Malta date to this period. A long historiographic controversy loomed over Medieval Muslim Malta. According to the "Christian continuity thesis", spearheaded by Giovanni Francesco Abela and still most present in popular narratives, the Maltese population continuously inhabited the islands from the early Christian Era up to today, and a Christian community persisted even during Muslim times. This was contested in the 1970s by the medieval historian Godfrey Wettinger, who claimed that nothing indicated the continuity of Christianity from the late 9th to the 11th century on the Maltese Islands – the Maltese must have integrated into the new Arab Islamic society. The Christian continuity thesis had a revival in 2010 following the publication of Tristia ex Melitogaudo by Stanley Fiorini, Horatio Vella and Joseph Brincat, who challenged Wettinger's interpretation based on a line of a Byzantine poem (which later appeared to have been mistranslated). Wettinger subsequently reaffirmed his thesis, based on sources from the Arab historians and geographers Al Baqri, Al-Himyarī, Ibn Hauqal, Qazwini, who all seemed to be in agreement that "the island of Malta remained after that a ruin without inhabitants" – thus ruling out any continuity whatsoever between the Maltese prior to 870 and after. This is also consistent with Joseph Brincat’s finding of no further substrata beyond Arabic in the Maltese language, a very rare occurrence which may only be explained by a drastic lapse between one period and the following. To the contrary, the few Byzantine words in Maltese language can be traced to the 400 Rhodians coming with the knights in 1530, as well as to the influx of Greek rite Christians from Sicily. Norman Kingdom of Sicily rule Malta returned to Christian rule with the Norman conquest. It was, with Noto on the southern tip of Sicily, the last Arab stronghold in the region to be retaken by the resurgent Christians. In 1091, Count Roger I of Sicily, invaded Malta and turned the island's Muslim rulers into his vassals. In 1127, his son Roger II of Sicily fully established Norman rule in Malta, paving the way for the islands' Christianization. Malta was part of the Kingdom of Sicily for nearly 440 years. During this period, Malta was sold and resold to various feudal lords and barons and was dominated successively by the rulers of Swabia, Anjou, the Crown of Aragon, the Crown of