Describe Justinian's reign in the Byzantine Empire, and identify his most important achievement.

The most important Justinian's achievements were architecture, culture, expanding the Empire, rebuilding Constantinople and he wrote the law to protect Christianity.

Explanation:

Justinian's reign marked the final of the Roman empire. He had a passion for art and culture. Because of that during his reign, he made changes and accomplishments in Roman empire.

Justinian surrounded himself with talented people and he was in a marriage with Theodora one of the most influential Byzantine empresses.

He rebuilt the Constantinople city, churches and during his reign, Ravenna was the most-known artistic center. He expanded the Empire and protected Christianity by writing laws about it, and he also wanted to suppress paganism. Hagia Sophia was the most important architectural and religious achievement.

Because of his achievements he was called ''emperor who never sleeps''. Also, Saint Justinian, and The Great Justinian.