The order takes its name from La Trappe Abbey or La Grande Trappe, located in the French province of Normandy, where the reform movement began. Armand Jean le Bouthillier de Rancé, originally the commendatory abbot of La Trappe, led the reform. As commendatory abbot, de Rancé was a layman who obtained income from the monastery but was not a professed monk and otherwise had no religious obligations. He possessed considerable wealth and was earmarked for an ecclesiastical career as coadjutor bishop to the Archbishop of Tours. However, after undergoing a conversion of life between 1660 and 1662, de Rancé renounced his possessions, formally joined the abbey, and became its regular abbot in 1663.
In 1664, in reaction to the relaxation of practices in many Cistercian monasteries, de Rancé introduced an austere reform. de Rancé's reform was first and foremost centered on penitence; it prescribed hard manual labour, silence, a meagre diet, isolation from the world, and renunciation of most studies. The hard labour was in part a penitential exercise, in part a way of keeping the monastery self-supportive so that communication with the world might be kept at a minimum. This movement spread to many other Cistercian monasteries, which took up de Rancé's reforms. In time, these monasteries also spread and created new foundations of their own.
In 1892, several congregations of reformed or "Trappist” Cistercians were united to form an independent monastic order with the approval of the pope, formalising their identity and spirituality as a separate monastic order.
One of the most notable Trappist theologians was Thomas Merton, a prominent author in the mystic tradition and a noted poet and social and literary critic. He entered the Abbey of Gethsemani in 1941 where his writings and letters to world leaders became some of the most widely read spiritual and social works of the 20th century. Merton's widely-read works include his autobiography, The Seven Storey Mountain, as well as New Seeds of Contemplation and No Man is an Island.
The first Trappist saint was Saint Rafael Arnáiz Barón, who was a conventual oblate of the Abbey of San Isidro de Dueñas in Dueñas, Palencia. His defining characteristic was his intense devotion to a religious life and personal piety despite the setbacks of his affliction with diabetes mellitus. He died in 1938 aged 27 from complications of diabetes, and was beatified in 1992 by Pope John Paul II and canonised in 2009 by Pope Benedict XVI.