What were Justinian's achievements? Choose all correct answers.

He built a huge domed cathedral called the Hagia Sophia, an enormous underground aqueduct, and a fabulous palace complex.

He doubled the size of the empire and ruled much of the Mediterranean world.

He created a code of law that helped unite the Byzantine Empire and later served as a model for the codes of law in many modern nations.

He moved the imperial capital from Rome to Byzantium, so it would attract people from all over the world.