1071
Battle of Manzikert
On a plain in eastern Anatolia, Alp Arslan's Seljuks routed the Byzantine army of Romanos IV and captured the emperor himself. Released on humiliating terms, Romanos returned to Constantinople to find himself deposed, blinded, and dying. Anatolia, the heart of Byzantine manpower for seven centuries, began slipping under Turkish settlement.
Byzantium loses Bari
After a three-year siege, Robert Guiscard captured the last Byzantine stronghold in Italy. Bari's fall ended five centuries of imperial presence in the peninsula. Southern Italy was now entirely Norman. Within weeks the Normans would be crossing the Adriatic to attack the Byzantine empire itself in earnest. The loss of Italy severed one of Byzantium's oldest connections to the western Mediterranean world.
Song Dynasty Yellow River Floods Devastate Northern China
The Yellow River, that perpetual menace, breached its dikes again, inundating vast stretches of Hebei and Shandong provinces. Hundreds of thousands of peasants were displaced; harvests drowned under yellow silt-water. The disaster strengthened Wang Anshi's argument that the state must intervene - must build, must plan, must tax the wealthy to fund the infrastructure that nature kept destroying. His opponents saw the flood as heaven's judgment on precisely those ambitions.
Fall of Ely and end of Hereward's rising
William the Conqueror built a causeway across the Fens and captured the abbey of Ely, scattering or executing most of the rebels holed up there. Hereward himself escaped into legend. The conquest of England was effectively complete, and Anglo-Saxon England was finished as a political entity for good. Within a generation the English language itself would retreat from court and law to the speech of peasants.