From around 780, Europe saw the last of the barbarian invasions and became more socially and politically organized. The Carolingian Renaissance stimulated scientific and philosophical activity in Northern Europe. The first universities started operating in Bologna, Paris, Oxford, Salamanca, Cambridge and Modena. The Vikings settled in the British Isles, France and elsewhere, and Norse Christian kingdoms started developing in their Scandinavian homelands. The Magyars ceased their expansion in the 10th century, and by the year 1000, a Christian Kingdom of Hungary had become a recognized state in Central Europe that was forming alliances with regional powers. With the brief exception of the Mongol invasions in the 13th century, major nomadic incursions ceased. The powerful Byzantine Empire of the Macedonian and Komnenos dynasties gradually gave way to the resurrected Serbia and Bulgaria and to a successor crusader state (1204 to 1261), who continually fought each other until the end of the Latin Empire. The Byzantine Empire was reestablished in 1261 with the recapture of Constantinople from the Latins, though it was no longer a major power and would continue to falter through the 14th century, with remnants lasting until the mid 15th century.