The new evangelical religious movement unleashed by Martin Luther already found favour in Livonia in the early 1520’s. Compared to the old-established territories of the Holy Roman Empire of the German Nation, development here in Livonia was quite rapid. This can partially be explained by the peculiarities of Livonia’s history: here ecclesiastical feudal lords traditionally had a very strong influence on secular matters. Growth in the self-awareness of the towns and the nobility, however, inevitably brought with it conflict with the church.

By that time the Catholic Church had started realising more and more the need to raise the level of education of parish priests and to improve pastoral work among the laity. The spread of humanism intensified this notion. Several editions of a high standard of works by church fathers and other recognised ecclesiastical authorities, and also entirely new theological and devotional literature were published at the outset of the 16th century. At the same time, the movement unleashed by Martin Luther and other reformers intensified. At its centre was the notion that reform of religious life was not possible within the framework of the Catholic Church and that a completely new approach was needed both doctrinally and organisationally.

There is no precise information on the content of the message disseminated by such reform-minded clergymen in the Livonia of the 1520’s. Information on Reformation-era Tartu is especially scant since most of Tartu’s document collections were already destroyed in early modern wars. Thus every new opportunity to become more familiar with Tartu’s Reformation history is extremely important. One such opportunity is the book collection of the preacher Johannes Block from the town of Stolp in Pomerania, which is preserved almost without any losses. Block’s collection is deposited at the Barth ecclesiastical library. The greater portion of Block’s books is digitised.

Block was active in Tartu in the interval 1514–1528, working initially as a catholic preacher at the Church of St. Mary as well as at Tartu’s cathedral. After losing both of these positions in the tumult of the Reformation events of 1524/25, Block initially remained in Tartu, rebuffed by new, radically disposed evangelical preachers, until in 1528 he was given the position of evangelical preacher in the service of the Count of Hoya, the Viceroy of Vyborg. At the end of his life (1532/34–1544) Block was active in the Pomeranian ducal city of Barth, rising to the position of reformer there. Johannes Block’s library, including entries found in books concerning the purchase of the works, and also the various ways Block calls himself, make it possible to cast more light on Block’s biography, which is known very fragmentally on the basis of other sources. The chance to follow his gradual spiritual development, however, from a clergyman who respected the doctrine and hierarchy of the Catholic Church to a Lutheran preacher is especially important and exceptional. This also allows us a glance at the history of Tartu’s early Reformation period, which was fraught with conflicts.