In Sicily they'd arrived via Normandy and were already Franked up a bit -- they had a two king dynasty I think, both named Roger. And the elder Roger wanted a well-rounded education, so he hired (egad!) an Arab tutor. Later on they drove the muzzies out of Malta -- Maltese being a Semitic tongue with a broad loan vocabulary and altered grammar (sez McWhorter).
Roger ruled over mostly Mohammadens in Malta and to some extent Sicily. They gradually converted to Christianity over 200 years, some under duress