The "Republic of Virtue" was a period in French history (1791-1794) where Maximilien Robespierre remained in power. Many proponents of the Republic of Virtue developed their notion of civic virtue from the writings of Jean-Jacques Rousseau. The "Republic of Virtue" was part of the de-Christianization of the French Revolution. The de-Christianization process included the closing of churches, Protestant and Catholic, as well as selling many church buildings to the highest bidders. Many churches became store-houses for arms or grain. The statues of kings on the cathedral at Notre Dame were beheaded. However, the largest step in the de-Christianization of France was the establishment of the Cult of Reason to replace Christianity. This, however, was rejected by Maximilien Robespierre because he was opposed to the atheistic ideals of the Cult of Reason. He believed that the idea of Reason was too abstract for the common person to grasp and that they needed a hierarchical religion to follow. As a result, he established the Cult of the Supreme Being in June 1794, but neither cult attracted many followers. The new French Revolutionary Calendar was created during the Republic of Virtue as well. The first year started on September 22, 1792, the beginning of the Republic. Twelve months of exactly thirty days each received new names derived from nature. Ten-day décades replaced the seven-day week, allowing for only one day of rest, eliminating the Sunday of the Christian calendar. This new calendar remained in practice for only nine years. Then Robespierre was beheaded by the National Convention.