One of the oldest complete suits of European armour was discovered in 1960 near the village of Dendra, in Southern Greece, but it remained unknown whether this armour was suitable for extended use in battle or was purely ceremonial. This had limited our understanding of the ancient Greek–Late Bronze Age–warfare and its consequences that have underpinned the social transformations of prehistoric Europe and Eastern Mediterranean. In a series of archeo-physiological studies, merging knowledge in archaeology, history, human physiology, and numerical simulation, we provide supporting evidence that the Mycenaean armour found at Dendra was entirely compatible with use in extended combat, and we provide a free software enabling simulation of Late Bronze Age warfare. A group of special armed-forces personnel wearing a replica of the Dendra armour were able to complete an 11-hour simulated Late Bronze Age combat protocol that we developed from a series of studies based on the available evidence. Numerical simulation of the thermal exchanges in Late Bronze Age warfare extended this conclusion across different environmental conditions and fighting intensities. Our results support the notion that the Mycenaeans had such a powerful impact in Eastern Mediterranean at least partly as a result of their armour technology.