Complex sentence: In 1625 Urban VIII opened the ceremonial doors for the Jubilee year, however, the amount of pilgrims was lower than expected due to wars in northern Italy and so the Pope suspended the declaration of indulgences outside Rome to lure the faithful to the city.
Split into simpler sentences: In 1625 Urban VIII opened the ceremonial doors for the Jubilee year. However the amount of pilgrims was lower than expected due to the wars in northern Italy and so the Pope suspended the declaration of indulgences outside Rome in an attempt to lure the faithful to the city.