Catholicism was Christianity as established by Jesus Christ. Prior to the Reformation there was just the Catholic Church and the Eastern Orthodox Church; after the Reformation, all the various Protestant Denominations arose..Catholic AnswerCatholicism is Christianity, and it was established by Jesus Christ in the first century, He sent the Holy Spirit to guide it always, and put St. Peter and his successors at its head as His Vicar on earth. The Eastern Rites split into two in the twelve century. The protestant revolt happened in the sixteenth century, and they tend to call themselves "Christians" in such a way as to exclude the Catholics who were Christians for fifteen centuries before the protestants were even a thought. In other words, Catholic Christianity came first.