In 1357, the 'Book of Hours' became a popular form of devotional literature in Europe, particularly among the laity. These illuminated manuscripts, often personalized, contained prayers and psalms for daily use, reflecting the growing importance of personal piety during the late Middle Ages. The production of these books marked a significant shift in religious practice and literacy, as they were accessible to a broader audience beyond the clergy.

The 'Book of Hours' influenced the development of vernacular poetry, as many texts were written in the local language, making them more relatable to the general populace. Poets began to incorporate themes of personal devotion and spirituality into their works, paving the way for later movements such as the Renaissance and the Reformation.