Patriarchy? Boo! Constantinianism? Boo! But according to some church history amateur named Jaroslav Pelikan, you can really only hate one. Amongst Constantine's reformulations of Roman law,
"socially, the most important were probably those that proscribed certain ancient Roman practices now deemed immoral and antisocial [such as] the Christian laws modifying the patria potestas, under which in ancient Rome the father of the family or clan had the right to decide the question of life or death for a newborn child, especially for one that was born deformed. Constantine struck down that provision of the patria potestas, thereby helping to initiate the legislation against abortion that was to characterize the legal and moral position of most nations in Christendom, both Eastern and Western, until comparatively modern times, but thereby also making it necessary to invent other forms of care for such unwanted children." (26).Should you know of a more blatant historical instance of patriarchy (a pater with archy over life and death) being forcefully dismantled, do tell.
Of course, that's not the story whole. Military action has its justifications, but it seems slightly contrary to the spirit of the crucifixion for Constantine to have melted down the nails from the true cross and have them "made into a bridle-bit and a helmet, which he used on military expeditions" (Socrates Scholasticus' Ecclesiastical History 1.17). I imagine CNN's history gophers for "God's Warriors" would love that last bit, while politely ignoring the first.