“After the death of John Tzimisces, a revolt broke out in the Macedonian region, led by the provincial governor of Macedonia. The rising took on serious proportions and became a war of liberation, which spread over the whole of Macedonia and sought to remove the greater part of the Balkans from Byzantine rule. On hearing the news of the rising, Boris II, the Tzar of the Bulgars, together with his brother, Romanus, fled from Constantinople, but was killed crossing the border; Romanus reached home, but could lay no claim to the crown because he had been castrated by the Byzantines.”

“Little by little he (samoil) gathered under his sway the whole Macedonian reion except Thessalonica, the old Bulgar territory between the Danube and the Balkan range, Thessaly, Epirus, part of Albania including Dyrrachium, and finally Rascia and Dioclea. The Bulgarian Patriarchate, abolished by Tzimisces, was also able to celebrate its revival under Samuel…………Politically and ecclesiastically, the new empire was the direct descendant of the empire of Symeon and Peter, and was regarded by Samuel and the Byzantines alike as being simply the Bulgarian Empire. For apart from Byzantium, only Bulgaria at that time possessed a tradition of empire with a patriarchate of its own. Samuel was entirely committed to these traditions. But in reality his Macedonian kingdom was essentially different from the former kingdom of the Bulgars. In composition and character, it represented a new and distinctive phenomenon. The balance had shifted towards the west and south, and Macedonia, a peripheral region in the old Bulgarian kingdom, was its real centre.”
Page 301-2.

An almost IDENTICAL situation to that of the East-West Roman Empire(s).

Just so you can see how irrelevant medieval terms are when it concerns today, on page 266 Ostrogorski says that the Bulgar Khan Symeon has refered to himself as Emperor of Romans on a seal, such was his desire to become the global emperor of all.

“For Basil II, the struggle with Samuel became his chief task and the annihilation of Samuel’s empire his life’s ambition. He seems to have sought the support of other Balkan rulers against the powerful Macedonian Empire….”
Page 307.

With the introduction of Christianity and Slavonic learning in Bulgaria, Boris assured that the Bulgar-Turks had seen their last days of influence in Bulgaria, it was now, due to the missionary work of Kiril and Metodi, a solidly Slav state.

“Constantine’s first step was to invent a Slavonic script (the so-called glagolithic alphabet); he then proceeded to translate the Bible into Slavonic (using the Macedonian Slavonic dialect).”
Page 229.

JOHN SKYLITZES, SYNOPSIS HISTORION

The Battle of Kleidion, 29 July 1014

Reigns of Basil and Constantine, c. 35 (ed. Thurn, pp. 348-9)