From good ole Wikipedia while looking under TSR.2. Apparently same engine core shared between TSR and Concorde.
"In June 1966 a complete Olympus 593 engine and variable geometry exhaust assembly was first run at Melun-Villaroche, Île-de-France, France. At Bristol, flight tests began using a RAF Vulcan bomber with the engine attached to its underside. Due to the Vulcan's aerodynamic limitations the tests were limited to a speed of Mach 0.98 (1,200 km/h). During these tests the 593 achieved 35,190 lbf (157 kN) thrust, which exceeded the requirements of the engine.
In April 1967 the Olympus 593 ran for the first time in a high altitude chamber, at Saclay Île-de-France, France. In January 1968 the Vulcan flying test bed logged 100 flight hours, and the variable geometry exhaust assembly for the Olympus 593 engine was cleared at Melun-Villaroche for flight in the Concorde prototypes."