At the Congress of Vienna (1814-15) the territory of Geneva was enlarged to cover 15 Savoyard and 6 French parishes, with more than 16,000 Catholics; at the same time it became a part of the Swiss Confederation. The treaty said that Catholic religion was to be protected, and that no changes were to be made without agreement with the Holy See. Later, Pope Pius VII made the cities of Geneva and Lausanne a new diocese of and part of Geneva diocese that was in France part of the French diocese of Annecy.