The territory of modern Albania was part of the Bulgarian Empire during certain periods in the Middle Ages and some parts in what is now eastern Albania were populated and ruled by the Bulgarians for centuries. Most of Albania became part of the First Empire in the early 840s during the reign of Khan Presian. Some coastal towns such as Durrës remained in the hands of the Byzantines for most of that period. The castles of the inner mountainous country remained one of the last Bulgarian strongholds to be conquered by the Byzantines in 1018/1019 during the fall of the First Bulgarian Empire — Tomornitsa. During the Byzantine rule Albania was one of the centres of a Uprising of Peter Delyan. The last Bulgarian Emperor to govern the whole territory was Ivan Asen II (1218–1241) but after his successors the Bulgarian rule diminished. Much of that area corresponded with the Bulgarian historical region Kutmichevitsa.