An 11th-century Description
This snippet is from Ibn Miskawayh, who wrote a history of the Buyids (though organized by caliphal reign) in Arabic in the 11th century. Here, he’s talking about the Byzantine emperor Basil (r. 976-1025)
Basil prospered in his empire and displayed political ability, sound judgment and strength of mind. For thirty-five years he kept up war with the Bulgarians, in which numerous engagements were fought; ultimately he conquered them, taking possession oftheir lands whence he expelled the greater number of them, settling Byzantines instead. He was famed for his justice and affection for Muslims, and I imagine that his long life and reign were due to his keeping his hands off their territory and his kindly treatment of such of them as came into his.
Source, p. 119.
An 11th-century Description
This snippet is from Aristakes Lastivertc’i, who wrote his history in Armenian in the 11th century.
Now as for the emperor himself, he went and concerned himself with [matters in] the western parts, for he had mastered the land of the Bulgars, their districts and cities which for a long time following the commencement of his reign, [waging] uneasy wars, he had been unable to get under control, But now favorable opportunities presented themselves, for the one who had held the land, [a man] victorious in warfare, had died, while his sons, because they did not reconcile themselves one with the other, surrendered, going to the emperor. For “A kingdom divided against itself cannot stand” [Mark 3.14]. Such was the case with the country of the Bulgars. Now the emperor removed the sons of the Bulgar tyrant from their inheritance, clan and family, and gave them places of habitation in the land of Byzantium. Then he treacherously assembled in one place all the troops of that land as if he were going to give them gifts and record their numbers, but then sent them without [chance of] return to the East. They came and ruined the land. Alas their coming to the East, and woe to the place where they moved about! Lo, [they were] a wicked and merciless people, a hard-hearted, assaulting people. This prophetic lament may appropriately be recited about them, “The land was like the garden of Eden before them, but after them, a desolate wilderness” [Joel II. 3]. We have said enough about this. Let us return to the course of our narration.
In the year 464 of our era  Bagarat, [king] of Abkhazia, died and his son, Georgi, succeeded him [1014-1027]. The emperor Basil sent him an edict which read as follows: “Abandon [those territories] which I gave to your father out of the Curopalate’s portion as a gift, and be prince solely over your patrimony.” But [Georgi] did not consent to this; rather, taking pride in his youth, he wrote a contrary reply: “I shall not give anyone even one single House [from the territory] over which my father held sway.” Now when the emperor heard this, he sent an army to forcibly master the land. The braves of Tayk’ came forth to resist [this army] near the great Uxtik’ awan, and they put the Byzantine army to flight, but in no way did they harm the city or other cultivated places. Yet this was the beginning of the destruction of the House of Tayk’.