Southern Italy, Sicily, and much of the Mediterranean was largely an extension of the Arab/Islamic world in the beginning of the Middle Ages. However, as the Normans and the Catholic church gained power, a new interest spawned in trying to rid the continent of these non-European invaders, and by 1300, they did just that.

A dialect of Arabic was historically the lingua franca in this region during this time period, but that has since been gone-- except for Malta. I don't understand how the dialect can persist in Malta, while it all but disappeared in Sicily very quickly after the expulsion in 1224 seemingly without a trace.

Wiki articles for context:
https://en.wikipedia.org/wiki/Emirate_of_Sicily
https://en.wikipedia.org/wiki/Siculo-Arabic
https://en.wikipedia.org/wiki/Islam_in_Malta
https://en.wikipedia.org/wiki/Maltese_language