The Giganto-Schism occurred sometime just after the establishment of the Trans-Vatican and the first RoboPope, Clagnor The Irrefutably Lethal. (This was during the first years of the Genetic Fruit-Topping Wars).
While the people of St. Tropezia were somewhat bemused by the dire calamities promised by the Trans-Catholic Church, they found themselves drawn irresistibly to the gigantic women of the saucy little planet, and formed the Giganto Creed.
In particular, they loved Our Lady of the Massive Legs and Leopard Skin Camisole (particularly when she was bathing).
The Giganto-Schism further widened when the Victoria Secret Galaxy joined the Corporate Imperium, and they unleashed their first catalog of “Euretro-Genita Coverings for the Monumental Goddess” collection upon the unsuspecting Trans-Vatican.
And when the RoboPope discovered that several of his Death Cardinals of Extreme Planetary Retribution kept copies of the catalog under their mattresses, the church never recovered.