The science behind the sword

The problem with iron swords, though, is that iron bends. To make a sharp, hard, cutting edge, you need steel – an alloy of iron and carbon. In the first millennium BCE, the Etruscans began to create alloys of steel and iron, making swords that had edges hard enough to cut through armour, yet which were also sufficiently flexible to withstand the shock of battle.

The Romans developed Etruscan technology, creating the blade that characterised the Roman military machine: the gladius. This short, stabbing sword was the weapon of the legionary and, armed with it, the Romans created their empire. But it was the longer sword employed by their cavalry, the spatha, that outlived Roman rule. As the Western Empire declined, many of the barbarian groups who were employed to defend it used the spatha. The weapon became the prototype from which the swords of the Anglo-Saxons and Vikings, the high points of western sword making, developed.

Perhaps the finest example of these swords is the one found at Bamburgh in Northumberland. Excavated in 1960 and rediscovered in 2001 (just in time, as it was about to be thrown into a skip), the Bamburgh Sword was forged in the 7th century. About 76 centimetres long when first made, the sword was passed down through the centuries until, some 300 years after it was forged, it broke. As an heirloom of kings and earls, the sword was not thrown away, but buried, until archaeologists excavated it, although at first they did not realise what they had found.

The Bamburgh Sword was made from six strands of iron, pattern-welded together. No other sword has been found with more than four. In pattern welding, the iron strands are heated, twisted and hammered together, over and over again. When finished, pattern-welded swords have striking swirling designs on them.

It was this tell-tale pattern that led, in part, to the end of pattern-welded swords. Every warrior wanted a weapon like this and, by the later Viking Age, armies had grown to a thousand or more men. In response, crafty swordsmiths began producing fake versions of these blades, which had an ordinary iron core and a thin pattern-welded layer on top.

With the arrival of massed armies, swordsmiths started to forge simpler, easier-to- make blades. The design of the swords
continued to change through the following centuries, to suit the fighting styles of the men carrying them. Blade styles also changed as armour improved, making it harder to cut through with a sword’s edge. As a result, the point of the sword became more important, being sharpened and hardened so that it could punch a hole through an enemy’s armour. Despite bullets largely replacing blades on battlefields, swords continued to be employed by soldiers into the 20th century, being used widely during the Russian Civil War (1918-1920) and the Sino-Japanese War (1937-1945).