December Observances December 8: Canonical Foundation of the Third Order of Mary Pope Pius IX, on September 8, 1850, delegated the Canonical Institution of the Third Order of Mary to the Cardinal Archbishop of Lyons. Cardinal de Bonald issued the official decree on December 5 of the same year, setting December 8 as the date of the actual establishment. Marist consider this institution of the Third Order as the Church's approval of the idea of a Marist lay branch, an idea that had been there from the beginning of the Society of Mary. This lay branch has now taken on many different forms throughout the world. ------------------------------------------------------------------------------------------------- Dec 8: Clothing of the first Marist Sisters at Cerdon (1824).