Answer:
He changed his official religion to Christianity.
Step-by-step explanation:
Four important and notable tasks that Emperor Constantine accomplished are the following:
1. He got victory in the civil war and become the sole emperor of the roman empire.
2. He gives legal rights to the christian that lived in his kingdom and at the end also accepted Christianity.
3. He also announced Christianity as the official religion of the empire.
4. He restructured the government and separate the civil and military authorities from the government affairs.