This unusual chair is called prayer chair (French name since 17th century "prie-dieu"). First used by the higher clergy during religious services in the early European Middle Ages, the prie-dieu became popular in the 19th century owing to the Gothic Revival and to a pietistic passion for family prayers.
The design of this prayer stand varied in time, eventually settling as a small, ornamental wooden desk furnished with a thin, sloping shelf for books or hands, and a kneeler. Sometimes, instead of the sloping shelf, a padded arm rest was provided. This type is useful for devotions such as the Rosary, which do not require a book, or for private, non-liturgical prayer.
Prie-dieu may be provided in church weddings for the bride and groom to kneel on during the service