The First Council of the Lateran was a very important event in the history of the Catholic Church. It was a meeting of all the important church leaders and it happened in Rome, Italy. It was held in the Lateran Palace, which was the home of the Pope. At this meeting they discussed a lot of things and agreed on some important rules and decisions which would shape the Catholic Church for many years to come. They talked about how priests should behave and how they should act in different situations. They also agreed that the Pope should have the highest authority and he should have the final say on decisions. The Council also set up rules for things like heresy and bishops, which are still followed in the Church today. Finally, the Council declared that all Catholics should go to Mass on Sundays which is still practiced today. So, the First Council of the Lateran was very important for the Catholic faith and still affects the Church today.