Bury Castle was a medieval moated site of possibly 14th century origin. Later, around 1470 it was strengthened as a fortified manor house. From the 12th Century the de Bury family held a manor here. In the mid 14th century it passed, by marriage, to the Pilkingtons.
In 1469 Thomas Pilkington obtained a licence from the King to fortify his manor house.
He was a powerful and wealthy noble and the rebuilding of his home was an expression of his high social status. However, as a Yorkist supporter, his fortunes declined with the death of Richard III and in 1489 Bury Castle passed into the hands of Thomas Standley, Earl of Derby. The building was superfluous to his requirements and was dismantled. Gradually, over the next century, stone was taken from the castle walls and the moat was filled with rubble and rubbish. By the 18th century brick structures were being constructed over the infilled moat and the castle site was effectively lost.
In 1865 new sewers were constructed in Castle Square and a number of poor brick structures were demolished. An antiquarian called Hardwick observed the sewer and undertook some excavation himself to record the remains of the castle. He found evidence to suggest a large rectangular building 82 by 63 feet with 6 feet wide walls, together with an enclosing buttressed wall about 123 by 113 feet, of 2 feet thickness. These discoveries led to the naming of the new street over the sewer as 'Castle Street' and provided inspiration for the design of the Castle Armoury facade. The remains of the lower outer wall are now exposed and can be seen to the front of the Armoury.
A leaflet explaining the history behind Bury Castle is available from Bury Tourist Information Centre, and all local libraries.