Coordinates: 51°28′45″N 0°36′34″W / 51.4791°N 0.6095°W / 51.4791; -0.6095

Windsor ( /ˈwɪndzər/) is an affluent^{[citation needed]} town and unparished area in the Royal Borough of Windsor and Maidenhead in Berkshire, England. It is widely known as the site of Windsor Castle, one of the official residences of the British Royal Family.

The town is situated 21 miles (34 km) west of Charing Cross, London. It is immediately south of the River Thames, which forms its boundary with Eton. Windsor and the surrounding areas contain some of the most expensive and desirable housing in the UK^{[citation needed]}. The village of Old Windsor, just over 2 miles (3 km) to the south, predates what is now called Windsor by around 300 years; in the past Windsor was formally referred to as New Windsor to distinguish the two.

The early history of the site is unknown, although the site was almost certainly settled many years before the medieval castle was built. Histories of the town note that the combination of the navigable river and the strategically placed hill point to the likelihood of continuous human settlement from early times. Evidence includes archaeological finds from Windsor, such as palaeolithic hand-axes, neolithic flint picks, Bronze Age swords and an Iron Age brooch. Although Roman remains are few, there is ample evidence of Anglo Saxon settlement in the area.

Berkshire ( /ˈbɑrkʃər/ or /ˈbɑrkʃɪər/, abbreviated Berks) is both a ceremonial county and a historic county of England. The administrative county of Berkshire including the Berkshire County Council were abolished in 1998. The county is often referred to as the Royal County of Berkshire because of the presence of the royal residence of Windsor Castle in the county; this usage, which dates to the 19th century at least, was recognised by the Queen in 1957, and letters patent issued confirming this in 1974.

The ceremonial county has the same boundaries as the former administrative county, but historically the county was not co-terminous with this. The county borders the counties of Oxfordshire, Buckinghamshire, Surrey, Wiltshire and Hampshire. Historically the county included several towns to the northwest of the county (including Abingdon, Didcot and Wantage) that were moved into Oxfordshire in 1974 boundary changes. At the same time the town of Slough was moved into Berkshire from Buckinghamshire.