Polybius famously claimed that Gaulish Celtic warriors were crippled in battle because their longswords bent upon impact and had to be straightened with the foot. Metallurgical spectroscopy of excavated La Tène Iron Age blades refutes the Roman account as wartime propaganda: Celtic smiths had mastered pattern welding, carburized high-carbon cutting edges, and quench hardening, producing weapons so mechanically superior that the Roman army discarded their native blades to adopt the Celtic design as the gladius Hispaniensis. wikipedia.org