Spiritus Sanctus

The Amazing Cappella Palatina of Roger II, Norman king of Sicily

The story that hasn't been written: Vikings from Norway harass the French, who grant them the Duchy of Normandy in northern France on condition they keep other vikings away, then later these same Latinized Norwegians, now known as Normans, conquer England in 1066, then even later, do the same in Sicily, building there a tolerant and multiethnic state that can create amazing and uplifting buildings like this Cappella.