St. Augustine's Monastery (German: Augustinerkloster) in Erfurt, central Germany, is a former church and friary complex dating from the 13th century.

Because of their role in the Reformation, all of these sites are considered to "represent one of the most important events in the religious and political history of the world".

[7] Building work continued, with the construction of the St. Katherine's chapel (German: Katharinenkapelle), the chapter house, the church tower, a cloister, and a longhouse and a new priory.

One was used to store cereal grains and the other for processing the woad plant to produce valuable blue indigo dye, for which Erfurt was renowned in the Middle Ages.

[3][8] The friary also had a notable Studium generale, an early form of university, led by Henry of Friemar the Elder (c.1245–1340), an Augustinian friar, philosopher, theologian and aesthetic writer.

He survived the storm and kept his vow, immediately leaving university and joining St. Augustine's Monastery as a novice friar on 17 July 1505.

They returned to St Augustine's in March 1511 and in September 1511 Luther left the friary permanently, to teach at Wittenberg.

[14][4] In his later role as the provincial vicar of Saxony and Thuringia, from 1515, Luther continued to pay visits to St Augustine's and other monasteries.

A fire in 1872 destroyed the interior of the upper storey of the former dormitory where the cell is located, but it was rebuilt in keeping with historical accuracy soon afterwards.

From this time the west wing of the monastery, together with the old priory, the library and the woad houses were used by the St. Martin's foundation, (German: the Martinsstift), a charity for the education of orphans and neglected children.

[2] A successful petition was made to King Frederick William IV of Prussia, who was a Lutheran, for funds to repair the church.

[2] From 20 March until 29 April 1850, the church was used for meetings of the parliament of the Erfurt Union, an unsuccessful attempt at a federation of German states.

[4] Towards the end of World War II, on 25 February 1945, the friary complex was considerably damaged in a British air raid.

The blast of air pressure from the explosions caused all the remaining buildings, including the Augustinian church itself, to lose their roofs, windows and doors.

[18] The basement of the friary library was a public air raid shelter, and many people were seeking refuge there at the time of the attack.

[20] In 1996, the first four sisters of the evangelical Communität Casteller Ring moved into rooms of the monastery, returning the building to a usage similar to what it had in the Middle Ages.

[2] In 2003, several scenes of the feature film Luther, starring Joseph Fiennes, were shot in the buildings of the monastery.

The Library of the Evangelical Ministry, with 60,000 volumes, one of the most important ecclesiastical collections in Germany, is housed in the monastery's former dormitory.

[25] The building of the modern 'Waidhaus' on the foundations and cellar of the medieval Woad houses that were destroyed in World War II was done in consultation with the Thuringia department for monument protection and archaeology.