Background and history
The ideal of the imitation of Christ has been an important element of Christian theology, ethics and spirituality. References to this concept and its practice are found in the earliest Christian documents, such as the Pauline Epistles.
Saint Augustine viewed the imitation of Christ as the fundamental purpose of Christian life, and as a remedy for the imitation of the sins of Adam. Saint Francis of Assisi believed in the physical as well as the spiritual imitation of Christ, and advocated a path of poverty and preaching like Jesus who was poor at birth in the manger and died naked on the cross. The theme of imitation of Christ existed in all phases of Byzantine theology, and in the 14th century book Life in Christ Nicholas Cabasilas viewed "living one's own personal life" in Christ as the fundamental Christian virtue.
Against this backdrop, the Devotio Moderna movement was started by Geert Groote who was highly dissatisfied with the state of the Church and what he perceived as the gradual loss of monastic traditions and the lack of moral values among the clergy. The initial focus of Devotio Moderna was the rediscovery of genuine pious practices and conversion and re-conversion of the lukewarm clergy. The Imitation was written within the Devotio Moderna community, as it was flourishing in Northern Europe, but grew far beyond that movement which came to an end with the Protestant Reformation.
The book was written anonymously in Latin in the Netherlands ca. 1418-1427 and Thomas à Kempis is generally accepted as the author. Several sources of authority, including members of his own order, name Kempis as the author, and various contemporary manuscripts, including one autograph codex, bear his name.
An 1874 edition from Tours
Joseph N. Tylenda S.J writes that the book was composed anonymously is "not surprising" since the author writes in the Imitation that one should "love to be unknown."(Book 1; Chap.2). Regarding the anonymity of the work, William C. Creasy also notes that the author of the Imitation wrote, "Do not let the writer's authority or learning influence you, be it little or great, but let the love of pure truth attract you to read. Do not ask, 'Who said this?' but pay attention to what is said."(Book 1; Chap.5).
By 1471, the manuscripts of the book were so frequently hand copied and passed across monasteries, that there are around 750 extant manuscripts of the Imitation. Thomas à Kempis's 1441 autograph manuscript of the book is available at the Bibliothèque Royale in Brussels. The first printed edition appeared in Augsburg in ca.1471-2. By the end of the 15th century, the book had more than 100 printed editions and translations in French, German, Italian and Spanish.
The book received an enthusiastic response from the very early days, as characterized by the statement of George Pirkhamer, the prior of Nuremberg, regarding the 1494 edition: "Nothing more holy, nothing more honorable, nothing more religious, nothing in fine more profitable for the Christian commonwealth can you ever do than to make known these works of Thomas à Kempis."
The number of counted editions exceeds 2000; 1000 different editions are preserved in the British Museum. The Bullingen collection, donated to the city of Cologne in 1838, contained at the time 400 different editions. De Backer enumerates 545 Latin and about 900 French editions. A critical edition was published in 1982. A new translation from the original Latin text into English by William Creasy was published in 2015.