In 1961, the Trevelyan family and their two young sons, built their own motorhome based on a Morris Commercial J2 van, which they took on holiday to the South of France.

[2] Auto-Sleepers core product developed through the adoption of the successful monocoque body, a two-piece clamshell glass-fibre unit which gave the living unit strength and a lack of edge joints, which on a traditional sandwich construction produce a weaker body which is prone to leaking.

The company developed rapidly and quickly became a product market leader in the United Kingdom, as well as exporting its vehicles to France, Belgium, the Netherlands, Luxembourg, Germany, Switzerland, New Zealand, Australia and Japan The Trevelyan family sold the business in 1997 to Steven Riley and Bill Cook, whilst retaining a small shareholding themselves.

The Service Centre is based in Willersey, near Broadway, Worcestershire, formerly managed by last family member involved with the business, Charles Trevelyan.

In June 2009, existing directors Geoff Scott and Mike Crouch acquired 100% of the shareholding via their company Trigano Group - the UK's largest dealer network of motorhomes, trading under the Marquis brand - returning Auto Sleeper into British private ownership.