Dorothy of Montau (c. 1347–1394), also known as Dorothea von Montau or Dorothy/Dorothea of Prussia, was a mystic and recluse in the cathedral church of Marienwerder (today’s Kwidzyn, Poland). She is also the first native-born saint of Prussia, after a bid for canonization begun in the fourteenth century eventually led to the recognition of her cult and confirmation that she could properly be called “saint” in 1976. According to the evidence of the several vitae, or saints’ lives, written about her, Dorothy was first inclined toward a religious life after a childhood accident; afterwards, she continued to maintain her devotions as a wife and mother. After the death of her husband, Dorothy placed her daughter into a monastery and pursued a religious life in the world before becoming enclosed as a recluse in the church of Marienwerder. She lived as a recluse under the direction of confessors John Marienwerder and John Reymann; after her death, the former composed and compiled numerous documents attesting to Dorothy’s holy life as part of an effort to have her canonized. Many of these sources survive; additionally, another separate text is attributed to Dorothy as author, framed as a letter from Dorothy to her daughter. This rich collection of texts paints a picture of Dorothy’s vivid mystical visions and affective spirituality, while also giving insights into the historical circumstances of her life.