Omurtag

The Byzantine–Bulgarian wars were a series of conflicts fought between the Byzantine Empire and the Bulgarian Empire which began after the Bulgars conquered parts of the Balkan peninsula after 680 AD. The Byzantine and First Bulgarian Empire continued to clash over the next century with varying success, until the Bulgarians, led by Krum, inflicted a series of crushing defeats on the Byzantines. After Krum died in 814, his son Omurtag negotiated a thirty-year peace treaty. Simeon I had multiple successful campaigns against the Byzantines during his rule from 893 to 927. His son Peter I negotiated another long-lasting peace treaty. His rule was followed by a period of decline of the Bulgarian state.

In 971 John I Tzimiskes, the Byzantine emperor, subjugated much of the weakening Bulgarian Empire by defeating Boris II and capturing Preslav, the Bulgarian capital. Samuel managed to stabilize the Bulgarian state with its center around the town of Prespa. Near the end of his rule, the Byzantines regained the upper hand, and under Basil II they won the Battle of Kleidion and completely conquered Bulgaria in 1018. There were rebellions against Byzantine rule from 1040 to 1041, and in the 1070s and the 1080s, but these failed. In 1185, however, Theodore Peter and Ivan Asen started a revolt, and the weakening Byzantine Empire, facing internal dynastic troubles of its own, was unable to quash the revolt.

Kanasubigi (Greek: ΚΑΝΑΣΥΒΙΓΙ), possibly read as Kanas Ubigi or Kanas U Bigi, was a title of the early Bulgar rulers of the First Bulgarian Empire. Omurtag (814–831) and his son Malamir (831–836) are mentioned in inscriptions as Kanasubigi.

The title khan for early Bulgarian rulers is an assumed one, as only the form kanasubigi or "kanasybigi" is attested in stone inscriptions. Historians presume that it includes the title khan in its archaic form kana, and there is a presumptive evidence suggesting that the latter title was indeed used in Bulgaria, e.g. the name of one of the Bulgars' ruler Pagan occurs in Patriarch Nicephorus's so-called breviarium as Καμπαγάνος (Kampaganos), likely an erroneous rendition of the phrase "Khan Pagan". Among the proposed translations for the phrase kanasubigi as a whole are lord of the army, from the reconstructed Turkic phrase *sü begi, paralleling the attested Old Turkic sü baši, and, more recently, "(ruler) from God", from the Indo-European *su- and baga-, i.e. *su-baga (an equivalent of the Greek phrase ὁ ἐκ Θεοῦ ἄρχων, ho ek Theou archon, which is common in Bulgar inscriptions). Another presumption is that the title means the great khan. This titulature presumably persisted until the Bulgars adopted Christianity. Some Bulgar inscriptions written in Greek and later in Slavonic refer to the Bulgarian ruler respectively with the Greek title archon or the Slavic title knyaz.