In the Middle Ages there was a lay-reform movement fired by zeal to return to the Gospel. Many of these lay penitent groups were drifting into heresy.
Munio de Zamora, Master General of the Dominicans at that time, decided that an organization of some sort had to be devised for these people. So in 1285, he published a “Rule for Penitents of St. Dominic.” This is the first international rule for the Third Order.
The Third Order has its origin in the desire of the laity for a radical, evangelical style of life based on the Dominican spirit of action and contemplation.
The Second Vatican Council stresses the role of the laity in several documents saying for example that the laity “exercise a genuine apostolate by their activity on behalf of bringing the gospel and holiness to men, and on behalf of penetrating and perfecting the temporal sphere of things through the spirit of the gospel.” We now use the term, “Dominican Laity”, to express our calling to share in prayer, study and mission. We remain in the world, single or married, and seek to grow in our pursuit of truth. Lay Dominicans enjoy the privileges of belonging to the Order and extend its effectiveness into the world in which we live and work.