It was one of the first school buildings in Alnwick and important to the history of the town. It was founded by the Duke of Northumberland in 1810 to commemorate the golden jubilee of George III. Although significantly altered and added to, the original school, known as the Jubilee School, can be identified. The building makes an important contribution to the character of the historic area of the town. The belfry and the commemorative plaque are particularly interesting.
A school for poor boys built in 1810-1 by the 2nd Duke of Northumberland to commemorate the Golden Jubilee of King George III. Originally known as the Jubilee School, it soon became known as the Duke's School. A new classroom, with connecting vestibule, was added between 1887 and 1898. Not long after this new and larger windows were inserted into both side walls, necessitating the construction of hald dormer, and the original leaded windows replaced with horned sashes. Around this time a new heating system was inserted. In 1904 a new school building was built on a different site and the old school was used as an elementary school. This school closed in 1921 and the building subsequently became the local library. The building consists of two main blocks, at right angles, linked by a vestibule. Both buildings are of one storey and are built of ashlar sandstone blocks with pitched slate roofs, the linking flat roofed vestibule is of similar construction. The original school is well detailed with a prominent belfry at its east end. Each side wall has a pair of original 5-light mullioned windows and a larger later 6-light mullioned window contained in a half dormer. The east gable has a stepped 14-light window and a similar window is partially visible in the west gable where there is also an external chimney stack, partially obscured by a later flat roofed extension. A stone plaque commemorating the foundation and opening of the school is attached to its north face. The later classroom is plainer with a 6-light stepped window in each gable and a modern extension on its east side.
The building was assessed for listing in 2008 following concerns over the future of the library. It did not meet the criteria for listing for the following reasons:
the original school has received later 19th and 20th century extensions to both gables and the later classroom has a large 20th century extension to its east side.
The original simple schoolroom was altered in the later 19th century by the insertion of new and larger windows in its side walls and the construction of half dormers.