Tertiaries (TERTIUS ORDO DE POENITENTIA; TERTIARII; FRATRES CONVERSI; also SORORES TERTH ORDINIS) is the name given to the members of a unions organized primarily in connection with the mendicant orders, but subsequently connected also with other orders. They are not required to live in the convent or undergo the three principal vows, and Were designed to retain their place in the world and represent the order in whose privileges they shared in the common walks of life. Their origin is, traced back to Norbert, the founder of the Order of Remonstrance's. The Templars, too, had a similar institution connected with their organization. The actual introduction of the-Order of Tertiaries was due, however, to Francis of Assisi, and dates back to 1221, the occasion for its creation being the effect produced by his preaching at Carnario, where men and women in great numbers dissolved the matrimonial relation in order to give themselves to repentance. All virtuous ant-orthodox persons were received into the order. The rule forbade participation in festivities, disputes, and offensive wars, and required works of charity, diligent religious exercises, an annual convocation for penance, and masses for the souls of the Tertiaries, living or dead. The order was governed by superiors periodically chosen. Its costume was to be of inferior stuff, neither wholly white nor black, and without ornament-an ash-colored coat and rope being finally chosen, over which ordinary secular clothing is permitted to be worn. The female tertiaries adopted a similar rule and costume, with the occasional addition of a white veil. The rule was confirmed by popes Honorius III, Gregory IX, and Nicholas IV. The order grew rapidly, and found favor in the highest circles, having numbered among its members the emperor Charles IV, kings Louis of France, Bela of Hungary, and Philip of Spain, queen Blanca of Castile, princess Anna of Austria, etc.
Towards the close of the 13th century a branch order was established among the male, and a century later among the female, Tertiaries to satisfy the craving of some for a stricter rule the Regulated Order of Tertiaries (Tertiari Regulares). After a rapid extension, this secondary order separated into different congregations, which, in substance, followed the Franciscan rule. The latter, in turn, gave rise to a series of congregations of Hospital Brothers and Sisters. They take the simple vows, and an additional one which binds them to care for the sick, and to live in hospitals or unions known as "families" and amenable to the bishops.
Tradition credits Domini with the founding of an order of Tertiaries, male and female. An association of nobles and knights was formed by him, after the conversion of the Albigenses, to recover the alienated property of the Church and convents. They were accordingly styled Milites de Militia Christi. Their vow bound them to that work, to diligent attendance on public worship, etc., and to the wearing of a garb of ashy hue. Their wives were pledged to promote the objects of the order, and were not allowed to marry again after becoming widows. In the middle of the 13th century this association became an order of penitents, assumed the Dominican rule, and was placed under the Dominican general, receiving the title of "Brothers, and Sisters of the Penanceof St. Dominic." Other orders, e.g. the Augustines, Minims, Servites, Trappists, etc., subsequently organized associations of Tertiaries. See Musson, Pragmat. Gesch. d. vornehmst. Monchsorden, etc. (Paris, 1751 sq.). — Herzog, Real-Encyklop. s.v.