Vlachs and Bulgars began a rebellion that led to the formation of the Second Bulgarian Empire

The reign of Isaac II, and more so that of his brother Alexios III, saw the collapse of what remained of the centralized machinery of Byzantine government and defense. Although the Normans were driven out of Greece, in 1185 the Vlachs and Bulgars began a rebellion that led to the formation of the Second Bulgarian Empire. The internal policy of the Angeloi was characterized by the squandering of the public treasure and fiscal maladministration. Imperial authority was severely weakened, and the growing power vacuum at the center of the Empire encouraged fragmentation.