The Byzantine Empire experienced cycles of growth and decay over the course of nearly a thousand years, including major losses during the early Muslim conquests of the 7th century. But the Empire's final decline started in the 11th century, and ended 400 years later in the Byzantine Empire's destruction in the 15th century. In the 11th century the empire experienced a major catastrophe in which most of its distant territories in Anatolia were lost to the Seljuks following the Battle of Manzikert and ensuing civil war.