Frogmore Mill was also known as Frogmoor Mill and Covent Mill. Frogmore Mill was named in a charter of Ashridge Monastery in the C13th and a mill is thought to have been in existence at the time of the Domesday Book (1086), then a corn mill, later changing to fulling then to papermaking in 1774.  It was known as Mill No 401 in the excise list.  By 1803 acquired by Fourdriniers.  Like Two Waters, it was bought by the Grand Junction Canal Co in 1818 and soon installed the first mechanised papermaking machine in the world in 1803; perfected by Bryan Donkin from Louis Nicolas Roberts design- the first Fourdrinier machine.  1810 Fourdriniers went bankrupt.  By 1817 leased by William Nash who died 1824 then run by his wife until about 1830.  In 1851 Burgess and Watt made paper from wood by a chemical process, now known as soda pulp, for a newspaper trial.  Linked to Two Waters Mill from 1853 to 1887 including use by Dickinsons.  In 1890 Sanguinetti started the British Paper Company for recycling which continued until May 2000, when the Apsley Paper Trail charity took on the site to preserve the legacy.