Theodosius II was a Roman Emperor who ruled from 408 to 450 AD. He was the son of Arcadius and became emperor at a young age. His reign is noted for the establishment of the Theodosian Code, a compilation of laws that helped to organize and clarify Roman legal practices. During his rule, Theodosius II faced various challenges, including threats from the Huns and internal conflicts within the empire. He is also known for his efforts to strengthen the city of Constantinople, including the construction of the Theodosian Walls, which provided significant protection against invasions.