During his reign, Justinian managed to seize areas the Roman Empire had lost to foreign invaders, rebuild Hagia Sophia, increase silk production, expand the Empire's art trade and strengthen the Orthodox Christian church policy. In addition, his strict taxation laws saw the Empire's annual revenue increase.
When Justinian began his reign he was determined to recapture some of the lands lost during periods of foreign invasion. As a result, he engaged in strict military campaigns across North Africa and the Germanic states. Although he successfully reinstated Revanna's capital status within Italy, he only had a few successes during the 530s, with later campaigns failing due to lack of revenue and support. However, he did manage to expand the Empire significantly.
In terms of trade, Justinian imported silk from the Chinese Empire, then manufactured it in factories within the empire. Alongside silk production, he produced works of art that would be sent to other leaders to establish consular relationships. He also attempted ambitious architectural projects, including the rebuilding of Hagia Sophia, which became an important Byzantine cathedral. In addition, when Justinian began his reign, the Empire's annual income was 5 million solidi; by the end, it was 6 million solidi.
In an attempt to promote Orthodox Christianity as the main religion, Justinian suppressed other practices. This included suppressing paganism and converting approximately 70,000 practicing pagans to Christianity.