Norse Balearic Islands? Norse Mediterranean Empire? AWESOME
Here's another timeline from my alternate-history message-board, After Palma: Vikings of the Balearics. Although the opening post does not specify a point of divergence, it seems that in 1110 AD, a Norwegian Crusading fleet is pushed back to Sicily by bad winds rather than continuing onto the Holy Land. There, spurred by a rise of Islamic piracy in the Western Mediterranean, the Norwegian King Sigurd attacks the Balearic Islands and parts of mainland Muslim Spain.
Goodies from this timeline include:
*Sigurd establishing himself as a power in mainland Italy after a dispute with the Pope.
*He bolsters his numbers by recruiting (converted) Muslim prisoners and seems both charismatic and terrifying enough to make it stick.
*Sigurd intervening in the politics of the Byzantine Empire and playing Emperor-maker. At one point he even absconds with most of the famous Varangian Guard.
*Ultimately Sigurd establishes an empire of multiple islands spanning the entire length of the Mediterranean and even imposes a protectorate on modern-day Tunisia.
Given Sigurd's complicated romantic/familial history (many children by different women, plus a step-nephew he is obligated to support politically), this Mediterranean Viking empire might not survive his death, but it'll certainly be interesting to watch.