The anti-clericalism of the French Revolution saw the wholesale nationalisation of church property and attempts to establish a state-run church. Large numbers of priests refused to take an oath of compliance to the National Assembly, leading to the Church being outlawed and replaced by a new religion of the worship of "Reason" but it never gained popularity. In this period, all monasteries were destroyed, 30,000 priests were exiled and hundreds more were killed.[180][181] When Pope Pius VI sided against the revolution in the First Coalition, Napoleon Bonaparte invaded Italy.