The history of the Bulldog began in the late 1960s, when the Beagle Company, builders of the then-popular, civilian Beagle B.121 Pup trainers, began developing a replacement for the RAFs fleet of aging de Havilland Chipmunk. Their design, the B.125 Bulldog, was fitted with a more-powerful 200-hp engine; a constant-speed propeller; longer, strengthened wings; and a strengthened fuselage structure. Before the prototype could be delivered, however, Beagles financial troubles led it to be liquidated in February 1970.
In May 1970, Scottish Aviation Limited (SAL) announced that it had acquired the development and manufacturing rights, and it resumed production of the Bulldog in 1971. The first customer was Sweden, with other nations following in rapid succession, including Malaysia, Kenya, Ghana, Nigeria, Jordan, Lebanon, Venezuela and Botswana, among others. The Swedish designated the aircraft the SK 61.
The largest customer by far was the Royal Air Force (RAF), which placed an order for 130 Bulldogs in 1972 to be used as primary flight-aptitude trainers for their flying cadets in the University Air Squadrons (UASs). The Bulldog served in this role until at least 2000, when it began to be replaced by more modern Grob Tutor T1 trainers. Increasingly, surplus Bulldogs have been appearing at the UK's Ministry of Defence (MoD) auctions, where many eager bidders from around the world have bought them in anticipation of restoring and flying them as reasonably-priced warbirds.