Black, grey, dark brown, light brown, and even light blue, the color of the Franciscan habit has evolved considerably over the centuries according to the customs and countries. The hagiographical accounts, and especially the first Vita written by Thomas de Celano in 1228, evoke the importance of the habit for Francis of Assisi as a social and moral marker. The saint thus chose a coarse tunic, synonymous with poverty, and in the shape of a cross. Today, the Franciscans have inherited this very simple habit, generally of a dark brown color. The observant Franciscan friars wear a round hood, while the conventual friars can wear a double hood. On their belts, there is usually a white rope made of three knots. They represent the three vows dear to the Franciscans: obedience, chastity and poverty. Finally, Franciscans are often seen wearing sandals.