The Norman kingdom established by Roger II in 1130 that briefly unified Sicily and southern Italy under a sophisticated multicultural monarchy blending Latin, Greek, and Arab traditions.
Passed by inheritance to the Hohenstaufen Holy Roman Emperors in 1194 when Henry VI conquered the kingdom, then divided in 1282 when the War of the Sicilian Vespers split it into the insular Kingdom of Sicily (under Aragon) and the mainland Kingdom of Naples (under the Angevins).
The atlas holds 4 border frames for Kingdom of Sicily — the shape you scrub through changes in 1130 · 1282 · 1340 · 1465.
Standard English-language history of the Norman foundation and character of the kingdom.
Norwich's vivid narrative of the Norman conquest and kingdom of the south, spanning Roger II — the cited work, in print (Penguin).