Instead of reusing the medieval chapel at Alnwick, the eighteenth-century chapel was adjacent to the library. It was fitted up from 1777 as a memorial to the 1st Duchess, who had died suddenly in 1776. This too made use of a Gothic revival style, with a Gothic lectern designed by Adam, but for which there is no surviving drawing; and chairs which are a close variant of those designed by Adam for Croome d’Abitot Church in 1761 (Adam volume 50/21). Adam’s scheme for a family tree motif mural on one wall is known to have been executed, but the exact variant design is unknown. This eighteenth-century chapel interior was demolished by Sir Anthony Salvin in the 1850s, and a new chapel was built as an extension to the keep.