Pope John XXIII opened the Second Vatican Council at St. Peter's Basilica, gathering over 2,500 bishops from around the world to modernize Catholic Church practice and doctrine. The council's reforms, including allowing Mass in vernacular languages and reshaping relations with other faiths, transformed Catholic worship worldwide over the following three years of sessions.
John XXIII stunned the Curia by announcing the council just three months into his papacy, telling stunned cardinals he wanted to throw open the church's windows and let in fresh air. Many in the Vatican bureaucracy viewed the elderly pope, elected as a presumed caretaker, as unlikely to attempt anything so ambitious.
The opening ceremony itself was a spectacle of continuity and change: a procession of bishops in centuries-old vestments walked into a basilica wired for live television broadcast, watched by audiences worldwide. John XXIII's opening address explicitly rejected the 'prophets of doom' within the church who wanted no change at all, insisting the council pursue mercy over condemnation.
Over four sessions stretching to 1965, the council would fundamentally alter Catholic life: Latin Mass gave way to vernacular liturgy, the church formally repudiated antisemitism and improved relations with Judaism, and lay Catholics were encouraged toward greater participation in worship and church governance. John XXIII died before the council concluded, but his gamble reshaped Catholicism for the modern era in ways still debated by traditionalists and reformers alike.
Key people: Pope John XXIII, Cardinal Giovanni Montini