Croat mosque on Sicily (1000 years ago)

These were most certainly South Slavic pirates from the Adriatic littoral who were quite active sea rovers during the period in question. These Sicilian Slavs are mentioned by Ibn Hauqal, an Arabic geographer and traveler from the second half of the 10th century, as well as by Yaqut, who also mentions a different quarter of Palermo whose name was "The Quarter of the Slavic Mosque". Eventually, the Sicilian Slavs become completely assimilated; the name Harat as-Saqaliba disappears with time and in the Latin-written documents of the 12-13th century it is displaced with the designation of Seralcadi (ar. Shari' al-qadi "Street of the Judge"). 

http://michalw.narod.ru/SlavicSpain.html
(prva Hrvatska Dzamija na Siciliji prije 1000 godina)