The name 'Dacorum' comes from the "Hundred of Dacorum" one of the ancient administrative units of Hertfordshire. The district was formed in 1974. In October 1984 the Council was granted borough status and became Dacorum Borough Council.
Dacorum covers 81 square miles of West Hertfordshire where it borders with Bedfordshire and Buckinghamshire. It extends Northwest almost from Watford, along the valleys of the Gade and Bulbourne rivers to the picturesque Chiltern Hills.
Dacorum consists of four main towns - Hemel Hempstead, Berkhamsted, Tring and Kings Langley - and many outlying rural villages. The villages of the borough are: Aldbury, Bovingdon, Bourne End, Bulbourne, Chipperfield, Cow Roast, Flamstead, Flaunden, Frithsden, Gaddesden Row, Great Gaddesden, Little Gaddesden, Little Tring, Long Marston, Markyate, Nettleden, New Mill, Northchurch, Potten End, Ringshall, Tringford, Water End and Wigginton
Dacorum has a population of 144,800 which is 13% of the total population of Hertfordshire. In terms of headcount, Dacorum is the largest of the Hertfordshire districts. There are 71,300 males (49%) and 73,500 females (51%) living in the borough. (Source: Office of National Statistics, Census 2011)
The main lines of communication through the Borough are the A41 bypass, the A4251, the Euston to Glasgow (West Coast main line) railway and the Grand Union Canal. The M1 runs down the eastern boundary and the M25 crosses the south-eastern tip of the Borough.