Excerpts from Books and Wikipedia
The Edict of Milan protected Christians and people of all faiths. [Furtado: 1001 Days]
"The two men met in Mediolanum (modern Milan) to celebrate Licinius’s marriage to Constantia and to issue an empire-wide proclamation that made Christianity legal, which was highly necessary given that both men had now wrapped themselves in the flag of God in order to claim the right to rule. . . . Christianity was the empire's best chance for survival." [Bauer: Medieval World, p. 6]