The Imitation of Christ is the most famous devotional book ever written. Indeed, it is second only to the Bible as the most popular Christian book in existence. It has been an integral part of the spiritual reading of the saints ever since it first appeared anonymously in 1418. It is not uncommon to read of saints whose whole library consisted of the Bible, the liturgical books and the Imitation; and its popularity extends even to the Protestant world. The author of this remarkable work, Thomas a Kempis, was born in Kempen, in the Diocese of Cologne, in 1379 or 1380. In 1399, he joined the Canons Regular of Windesheim, where he remained until his death in 1471, twice being elected subprior.
The Canons Regular of Windesheim were among the leaders of the reforming movement in Northern Europe at this time. It was the period of declining mediaeval unity, which nonetheless produced many of the works we think of as most characteristically mediaeval the Divine Comedy, the Dialogue of St. Catherine of Sienna and the writings of the Rhineland mystics. The Canons of Windesheim were concerned not only with the improvement of morals among the clergy, but also with extending and deepening the spiritual life of the laity in the promotion of the Devotio Moderna, a form of spirituality which finds its finest expression in The Imitation of Christ.
As Christopher Dawson has observed, the spirituality of this period "concentrated its attention on the Humanity of Jesus, on the contemplation of his Life and Passion, and on the practice of the Imitation of Christ. These are the characteristic notes of mediaeval devotion, from the time of the reforming movement, down to the Protestant Reformation, from St. Anselm and St. Bernard to St. Francis and St. Bonaventure, down to the Yorkshire hermit Richard Rolle and Thomas a Kempis." We might mention as particular influences to be found in the Imitation: the Sacred Scriptures, St. Augustine, St. Bernard, and the school of Windesheim.
But these are technicalities of interest to the scholar, but apt to be misleading to the general reader: for the Imitation is a masterwork with a flavour very much its own, and cannot readily be mistaken for any other book. It is presented here in its best known English translation: that of the Venerable Richard Challoner (1691 - 1781), Vicar Apostolic of the London district in penal times, and perhaps the greatest English Catholic figure of the eighteenth century.