Justinian I.
Explanation:
The Roman have had their own unique set of laws that they implement on all new territories that they have conquered. Everyone had to obey these laws and respect them. The problem was that as the society was becoming more and more developed the Roman laws started to gradually lose sense or to be badly formatted for the changed circumstances, thus creating lot of confusion.
Justinian I decided to change this. He took the Roman laws, sorted them out properly and in accordance to the needs of the people and the state. He then changed some and also implemented some new ones. All in all, Justinian managed to create a better organized, more developed, practical, and modern set of laws. He created the Justinian Code.