The_Balkans_during_the_early_Migration_Period First_Bulgarian_Empire

the eastern balkan peninsula inhabited thracians group of proto-indo-european tribes. whole region far north danube river gradually incorporated roman empire 1st century ad. decline of roman empire after 3rd century ad , devastating invasions of goths , huns left of region devastated, depopulated , in economic decline 5th century. empire s successor, eastern roman empire, called later historians byzantine empire, not exercise effective control in these territories other in coastal areas , cities in interior. nonetheless, never relinquished claim whole region danube. series of administrative, legislative, military , economic reforms improved situation despite these reforms disorder continued in of balkans. reign of emperor justinian (r. 527–565) saw temporary recovery of control , reconstruction of number of fortresses after death empire unable face threat of slavs due significant reduction of revenue , manpower.