During the Cold War, the G3 was one of the world’s pre-eminent battle rifles. Developed in France and Spain after 1945, the rifle was produced by the German arms manufacturer Heckler & Koch. Adopted by more than 40 countries and produced on licence by many more, it was widely employed during colonial wars in Africa, insurgencies in Latin America and conflicts in the Middle East, but perhaps its widest use was in the Iran–Iraq War. Variants of the G3 have also seen substantial usage among Special Forces including Britain’s Special Boat Service and the US Navy SEALs. Semi-automatic versions, especially the HK91 and HK93, remain popular in the United States, and the G3-derived HK11 and HK21 family of light machine guns have also been widely adopted by military and law-enforcement units across the world. Fully illustrated with specially commissioned artwork, this study examines one of the iconic weapons of the Cold War era.