Three years after Italy removed the last Islamic base out of Sicily ending the +450 year Islamic reign the first crusade started. Similar with Spain in 1492 the year celebrated as the last year of the 781-year Islamic law in Spain.
The Muslim Sack of Rome never actually got into the city. They raided outlying churches, mostly.
The guys who finally reconquered S. Italy and Sicily weren't Vikings. Their ancestors had been, but in the previous century or so they'd intermarried extensively with the pre-Viking inhabitants of Normandy and become the Normans, a peculiarly aggressive sub-species of French nobility.