Upper Mill is referred to as Castle Mill in early documents not only because of its close proximity to the Castle but also because it ground the flour, which would have been used in the Castle kitchens.
The mill and a number of the mill cottages were demolished in 1926 when the Music Department buildings of Berkhamsted were developed. The mill stones can be seen in the school’s gardens. A commemorative wall was built over the mill race in Mill Street with a Latin inscription which translates as:
Here for a thousand years the old mills stood And gave us bread; Here now our School in the rival motherhood Feeds minds instead.
Castle mill site used everything from cottages to school buildings and offices.
Lower Mill was situated on Bank Mill on the site which is now occupied by the Old Mill House Hotel. An eighteenth century lease refers to the fittings of the mill, which in the kitchen included a spit rack and a bacon rack in addition to two bars in the windows.
By the early 1900’s the river Bulbourne had begun to dry up around Lower Mill. This lack of water, which was needed to drive the waterwheel, meant that the mill was forced to close. A serious fire in the 1890s caused a great deal of damage to the machinery and structure of the mill. The iron watermill remained in situ for many years until it was eventually removed for wartime salvage.
n 1910 Castle Mill or Knowles Mill was built by the bridge at Lower Kings Road. The mill was built for J.G. Knowles and son, corn forage and seed merchants and was used to manufacture animal feed. The mill took full advantage of its position, a small wharf allowed grain to be delivered at one side of the building by canal boat, whilst wagons transported grain by road on the opposite side of the mill. The mill closed after the Second World War and is now occupied by offices.
By The Dacorum Heritage Trust Ltd
5th May 2010