Lamentation of a Sinner is a religious work written by Catherine Parr, the sixth and final wife of King Henry VIII of England. It was published posthumously in 1547, the same year of Parr's death. The book is a reflection on the author's spiritual journey and her search for truth and salvation.

The main theme of the book is the importance of prayer and repentance, as well as the need for a personal relationship with God. Parr discusses her own struggles with sin and the fear of damnation, but also offers hope and comfort to readers who may be experiencing similar doubts and fears.

In addition to her personal reflections, Lamentation of a Sinner also includes excerpts from the Bible and other religious texts, as well as prayers and hymns that were popular during Parr's time.

One of the notable aspects of the book is its emphasis on the importance of women's spiritual education and the role of women in religious life. Parr herself was a well-educated woman who was deeply committed to her faith, and she believed that women had a vital role to play in spreading the gospel and ministering to others.

Overall, Lamentation of a Sinner is a powerful and thought-provoking work that offers insights into the religious beliefs and experiences of one of England's most fascinating historical figures. As the only book known to have been written by a queen consort of England, it is a unique and valuable contribution to the history of both literature and religion.