Emperor Justinian I was a master legislator. He reorganized the administration of the imperial government and outlawed the suffragia, or sale of provincial governorships. He also sponsored the Codex Justinianus (Code of Justinian) and directed the construction of several new cathedrals, including the Hagia Sophia. In these and other domestic affairs, Justinian excelled. On the foreign front, he struggled. His empire warred constantly with the Persians in the east and the barbarians in the north and west. Justinian鈥檚 forces ultimately held off the Persians, but they did not hold off the barbarians.