(Source)
The formerly-Catholic Society of St Pius X triggered the schism by consecrating bishops without the Pope’s approval, a key part of the ceremony for Catholic believers.
The group has fought with the broader Church for decades on Vatican II reforms. This included things like “Mass should be offered in languages other than Latin” — but SSPX is generally seen as mostly being opposed to Vatican II’s attempt at building peace between Catholicism and people of Jewish & Muslim faiths.















