Original: At the Congress of Vienna of 1814-15, the territory of Geneva was extended to cover 15 Savoyard and six French parishes, with more than 16,000 Catholics; at the same time it was admitted to the Swiss Confederation.
Simplified: 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.