Monmouth School was built 1860-65 and designed by William Snooke. It replaced the Free Grammar School of 1614 which was completely demolished. The school buildings have been greatly added to since, but the Victorian build remains distinct, although the uses have changed, particularly the Schoolroom being adapted for use as the Library. The historic development of these buildings is unclear in the case of the chapel, which includes the foundation stone dated 1864 in the north wall, but this could well have been reset and the earliest glass in the Chapel is dated 1879. However, the blocked windows in the east wall show that it does pre-date the adjoining Day Houses, but it seems to have been developed further in the 1870s, Bradney says it was enlarged in 1875. The Master's House which stood to the west of the Schoolroom, seen in photographs from the late nineteenth century, was demolished to make way for the Henry Stock extension of 1895-6. They consist of a group of individually listed buildings built of coursed rock faced red sandstone with Bath and Forest of Dean stone dressings and Welsh slate roofs.

Source:- Cadw Listed Buildings , NJR 11/01/2011