Cited from the book:

“At the beginning of the sixth century, the Western Roman Empire was already a thing of the past. Those who dreamed of a reunited empire and a restored world civilization saw their only hope in a counteroffensive from the Eastern emperor. When Justinian ascended the throne of Constantinople in 527, the prospects for a conquest of the West seemed quite favorable. The barbarian kingdoms of the Ostrogoths, Vandals, and Visigoths had somewhat declined, and each was governed rather weakly.

Justinian, a man of Illyrian or Albanian blood, was in his forties when, in 527, he donned the imperial purple, the Byzantine symbol of empire. For the previous nine years, he had been the real ruler, guiding and assisting his uncle, an illiterate old soldier whom chance had raised to the throne in 518.

Justinian had recently married Theodora, a beautiful young actress whose earlier career had given rise to much gossip. Theodora was a brilliant woman who understood that she had a past to redeem. Whether or not she was always virtuous is debatable, but she was certainly always prudent. She possessed the spirit of an empress and surpassed her husband in courage and determination.

Justinian was not a great man by nature, but with his strong sense of duty and capacity for tireless work, he became a great figure in history. In foreign policy, he had two guiding ideas: to establish a lasting peace with Persia in the East, and to restore the Roman Empire in the West. He achieved limited success in both efforts.

Circumstances forced him to fight Persia several times; and although he had Belisarius, the most outstanding general of his century, the Persians usually maintained the upper hand. Nevertheless, toward the end of Justinian’s life, they offered the aging emperor a truce, provided he paid them tribute.”

Source:
A History of the World, Vol. I – to 1500. Author: Chester G. Starr et al. Publisher: Rand McNally & Co., Chicago, 1960