there is evidence of some limited prehistoric occupation around the watford area, with a few celtic and roman finds, though there is no evidence of a settlement until much later. watford stands where the river colne could be crossed on an ancient trackway from the southeast to the northwest. watford's high street follows the line of part of this route. the town was located on the first dry ground above the marshy edges of the river colne. the name watford may have arisen from the old english for "waet" (full of water – the area was marshy), or "wath" (hunting), and ford. st albans abbey claimed rights to the manor of cashio (then called "albanestou"), which included watford, dating from a grant by king offa in ad 793.