<Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The First Vatican Council (Latin: Concilium Vaticanum Primum) was convoked by Pope Pius IX on 29 June 1868, after a period of planning and preparation that began on 6 December 1864 . This, the twentieth ecumenical council of the Catholic Church, held three centuries after the Council of Trent, opened on 8 December 1869 and adjourned on 20 October 1870 . Unlike the five earlier general councils held in Rome, which met in the Lateran Basilica and are known as Lateran councils, it met in the Vatican Basilica, hence its name . Its best - known decision is its definition of papal infallibility . </P> <P> The council was convoked to deal with the contemporary problems of the rising influence of rationalism, liberalism, and materialism . Its purpose was, besides this, to define the Catholic doctrine concerning the Church of Christ . There was discussion and approval of only two constitutions: the Dogmatic Constitution on the Catholic Faith and the First Dogmatic Constitution on the Church of Christ, the latter dealing with the primacy and infallibility of the Bishop of Rome . The first matter brought up for debate was the dogmatic draft of Catholic doctrine against the manifold errors due to rationalism . </P> <P> This council was summoned by Pope Pius IX by a bull on 29 June 1868 . The first session was held in St. Peter's Basilica on 8 December 1869 . Preliminary sessions dealt with general administrative matters and committee assignments . Bishop Bernard John McQuaid complained of rainy weather, inadequate heating facilities and boredom . Bishop James Roosevelt Bayley of Newark, New Jersey, noted the high prices in Rome . When Lord Houghton asked Cardinal Manning what had been going on, he answered: </P>

When was the first vatican council held and what two topics were discussed