Yes, I recently lectured to my students on how big the mistake was for the churches and pastors to let Constantine call the Council of Nicea.--------------------------------------------------------------------------------------------------------------------
No doubt the universal church has morphed a lot in the past 1900 years. The major milestone on the timetable is when Constantine consolidated the universal church folk(Catholic=universal), circa 325 C.E. See the words of Constantine at the Council of Nicea, which he called. This was quite a conclave of universal churchmen, probably not dressed in sackcloth. This universal church error started a lot of the apostasy, long before Constantine and Helena gathered their icons and married a Church with the State.
Certainly not before Constantine, making your argument against Christmas in error.Answering the question: Why did the religion Catholicism start and what year did Catholicism start?
Yet at that time there was no pope, no bishops ruling over groups of churches, no transubstantiation, no purgatory, no confession, no "holy relics," no Mariolatry, no praying to the saints, no penance, no priesthood in the Catholic sense, etc., etc. So how was there a Catholic Church before Constantine, or even before Gregory the Great?Interesting: Constantine moved his offices to Constantinople, named for himself of course. He in effect split his universal church into East and West. When the West tried to Lord over the East about the papacy there was a serious split, which still exists.
And once again relating this to the OP (which you consistently fail to do), this all means that no, the Catholics did not invent Christmas (which is not "Christ mass," as I have linguistically proven, which proof you have let stand by not replying).