Gloucestershire is situated at the head of the Severn estuary, and is variously described as being in the south-west midlands, the south-west of England or the Welsh borders, all three of which are true. To the west it is bordered by Monmouthshire (Wales) and the Severn estuary, to the north by Herefordshire (Welsh borders or Marches) and Worcestershire, to the north-east by Warwickshire (Midlands), to the east by Oxfordshire (south Midlands), to the south by Wiltshire and the south-west by Somerset (both south-west England). It is about 55 miles long by 33 miles wide.
The county name means, as with others of similar format, the county based on Gloucester. For the latter, the -cester ending means it was a Roman camp (from the Old English ceaster), while the first part is a corruption of the Roman name of the city, Glevum. Glevum is derived from the Celtic descriptive root (not the name) describing the river (the Severn), glev- meaning "bright" or "shining". It consists of four distinct geographical areas. The western part is largely occupied by the hilly Forest of Dean and the Wye Valley, the eastern half by the limestone Cotswold Hills, with the very fertile Severn Valley in between. In the extreme south-west a small area is effectively a suburb or dormitory area for the city of Bristol. Bristol itself has at various times and for various purposes been considered to be a part of Gloucestershire, a part of Somerset, shared between the two, a part of the short-lived count of Avon and (as now) completely independent.
The county has a small coalfield in the Forest of Dean, but this has not led to major urban growth in that area, which remains largely woodland with a few small towns. The last mine closed some years ago, leaving forestry, tourism and sheep rearing as the main activities. The Severn valley is ideal cattle country, while on the Cotswolds arable farming has largely replaced the traditional sheep rearing. Many of the Cotswold towns had their prosperity based on woollen manufactures from the local sheep, but now rely on a combination of small-scale light industry and continuing operation as market towns serving their immediate locality.
Numerous burial mounds and the finding of stone and bronze tools and weapons show that the area now known as Gloucestershire was well-populated during the Neolithic and Bronze Ages, while hill forts along the Cotswold escarpment and many burials and artefacts show it was important during the Iron Age. The Romans had several major roads in the area as well as two cities (now known as Cirencester and Gloucester). Some time after the departure of the legions the Saxon Hwicce took their place, although being far to the west of the Saxon landings this was one of the later parts of Britain to fall under their control.
The Hwicce eventually became a subsidiary kingdom under the overlordship of King Offa of Mercia, and after his death the area was absorbed into the expanding kingdom of Wessex. After the Norman Conquest Gloucestershire became a part of the fortified boundary with Wales, leading to the construction of great castles at Berkeley, St. Briavels and Gloucester. Several of the battles between Stephen and Matilda took place in the county. During the Wars of the Roses victory at the battle of Tewkesbury in 1471 sealed Edward IV's victory over the Lancastrians and his hold on power. During the Civil War Gloucestershire, especially the Severn Valley, was the scene of much military activity, and the city of Gloucester was the site of a major siege.