The Byzantines survived during the 8th century and, beginning in the 9th century, took back parts of the conquered lands. In 1000 AD, the Eastern Empire was at its largest point, and culture and trade flourished. However, the expansion was suddenly stopped in 1071 at the Battle of Manzikert. This finally made the empire start becoming weaker. After centuries of fighting and Turkic invasions, Emperor Alexius I Comnenus called for help from the West in 1095.