 Originally a Tudor building, dating from 1546 for Sir Richard Morrison, it was substantially remodelled in the 17th and 19th centuries and ultimately demolished in 1927.The surrounding Cassiobury Park was turned into the main public open space for Watford.St Albans Abbey claimed rights to the manor of Cashio (then called "Albanestou"), which included Watford, dating from a grant by King Offa of Mercia in AD 793.