The western dimension of early medieval Bulgaria
The division of early mediaeval Bulgarian state to West and East was defined, firstly, by formation the state territory of Bulgaria in the 7th-10th cc., and secondly, by the role of East and West in the political and administrative division of the Byzantine Empire. The Bulgarian West was shaped by the territorial development of the early mediaeval state towards Adriatic seashore, and by the missionary activities lead by the disciples of St. Constantine-Cyril and Methodius. By the same time Bulgaria was seen by Constantinople as part of Byzantine West given to Bulgars as allies. The confrontations between Bulgaria and Byzantium during the reigns of Symeon (893–927) and Samuil (976–1014), from the Bulgarian side were formulated as pretensions for all Byzantine West, and from the Empire were seen as rejection of obedience which deprived the Bulgars from the right to rule given to them land – Zagora.