The Leyland National was conceived as a joint venture between British Leyland and the National Bus Company to replace all the rear-engined single-deckers in the British Leyland Group the AEC Swift, Leyland Panther, Daimler Roadliner, single-deck Daimler Fleetline, and Bristol RE.
The Leyland National was built at a new factory at Lillyhall in Cumbria and had several novel features, including integral construction, a sophisticated heating and ventilation system that meant a rear pod on the roof, and a turbocharged 8.3-litre horizontal Leyland engine. Most Leyland Nationals were 10.3 or 11.3 metres long and the first was delivered to Cumberland Motor Services in March 1972, registered ERM 35K. Over 7,000 Leyland Nationals were built, but it never achieved its full production targets due to the advent of one-person-operated double-deckers. The last Leyland National was registered C49 OCM and delivered to Halton Transport in November 1985.