Oliba spent his time and energy defend the property and rights of churches against attacks by his manor. In 1011, he went to the Vatican to meet the leader of the Roman Catholic Church, Pope Sergius IV, and he won a number of bulls, which are papal rulings, for his monasteries. These papal bulls had significant power: the Pope, whom medieval Catholics considered God's representative on earth, said that the monasteries and lands owned were under the protection of St. Peter and the attack on the monastery was an aggression against the authority of the Pope.