Some remarkable military invention is said to have contributed to the successful defense of Constantinople against the Arabs in 677. What could it be?
During the siege of 672-678, the Byzantines apparently first used Greek fire – a mixture of oil, resin and sulfur with saltpeter. Now such a mixture is called gunpowder (if it is solid and explodes) or napalm (if it is liquid and burns). It cannot be extinguished with water because it contains a lot of oxygen.
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