Emperor Theodosius II ruled the Eastern Roman Empire from 408 to 450 AD. He became emperor at a young age and was known for his strong commitment to Christianity, making it the official religion of the empire. His reign saw the construction of the Theodosian Walls around Constantinople, which provided significant protection to the city. Theodosius II is also recognized for his efforts in codifying laws, resulting in the Theodosian Code, a compilation of legal texts that influenced future legal systems. His reign was marked by both internal challenges and external threats, including conflicts with the Persian Empire and various barbarian groups.