The Wild Geese

Allen Faulkner (Richard Burton), a British mercenary and former army colonel, arrives in London to meet the wealthy and ruthless merchant banker Sir Edward Matheson (Stewart Granger). The latter proposes a risky operation to rescue Julius Limbani (Winston Ntshona), the liberal but imprisoned President of a Southern African nation who is due for execution by General Ndofa, the man who deposed him. President Limbani is held in a remote prison in Zembala, guarded by a unit of General Ndofa's personal troops known as the "Simbas". Read more on Wikipedia.