The earliest formal Third Orders date back to the 13th century, though similar associations of people based certainly existed before then. The timing isn’t particularly surprising, given the rising popular interest in access to the religious life at the time. The Humiliati were the first official Third Order, but the best known is the Third Order of St. Francis. It’s uncertain exactly how it came about,*** but according to the story, their Rule came directly from Francis himself.
The Dominicans and Carmelites soon gained their own Third Orders. The Lay Carmelites came about much as the Fransican Third Order did. The Dominican Third Order, on the other hand, originated as a group of Franciscans who were heavily influenced by the teachings of Dominican friars.
The reaction to the creation of Third Orders was not entirely positive. Several groups ran into trouble with their city governments because their Rule forbade them to bear arms. Individual tertiaries, like Catherine of Siena, often met with significant resistance from their families.
There were, and still are today, two sorts of tertiaries: regular and secular. Third Orders Regular, as they are known, existed almost from the beginning, but weren’t officially a distinct group until the 15th century. They take vows and live in organized communities. Seculars make less binding promises and usually live separately, though they still have a strong connection to their community.
Well-known medieval tertiaries include the Franciscans St. Elisabeth of Hungary, St. Rosa of Viterbo, and Dante Alighieri, as well as the Dominican St. Catherine of Siena.
*So called mostly because the male order was founded first. This was generally the case throughout the Middle Ages, with the notable exception being the beguines, who were never really unified enough to get that sort of formal recognition.
**There are, for example both Anglican and Lutheran Orders of St. Francis, which function as and consider themselves part of the Franciscan Third Order. The Lutheran one in the US is, I believe, affiliated with the ELCA.
***Thomas of Celano’s Vita prima claims that Francis started the Third Order, but there is also evidence for a more independent community that only later claimed to have been created by him.
Barber, Malcolm. The Two Cities: Medieval Europe 1050-1320. London: Routledge, 1993.
Bynum, Caroline Walker. Holy Feast and Holy Fast: the Religious Significance of Food to Medieval Women. Berkeley: University of California Press, 1987.
Cook, William R. and Ronald B. Herzman. The Medieval Worldview: an Introduction. New York: Oxford University Press, 2004.
Kienzle, Beverly Mayne and Pamela J. Walker. Women Preachers and Prophets thorugh Two Millennia of Christianity. Berkeley: University of California Press, 1998.
Stephenson, Carl and Bryce Lyon. Mediaeval HIstory: Europe from the Second to the Sixteenth Century. New York: Harper & Row, 1962.
Gobry, Ivan. Saint Francis of Assisi. Ignatius Press, 2006.
Third Orders - Catholic Encyclopedia
History of the Franciscan Third Order Regular - The Franciscan Friars, TOR
tssf.org - Third Order, Society of St. Francis [The Anglican Third Order of St. Francis, Province of the Americas]
lutheranfranciscans.org - Order of Lutheran Franciscans