Adopted from the Celts in the 1st century BC, the spatha, a lethal and formidable chopping blade, became the primary sword of the Roman soldier in the Later Empire. Over the following centuries, the blade, its scabbard, and its system of carriage underwent a series of developments, until by the 3rd century AD it was the universal sidearm of both infantry and cavalry. Thanks to its long reach, the spatha was the ideal cavalry weapon, replacing the long gladius hispaniensis in the later Republican period. As the manner in which Roman infantrymen fought evolved, styles of hand-to-hand combat changed so much that the gladius was superseded by the longer spatha during the 2nd century AD. Like the gladius, the spatha was technologically advanced, with a carefully controlled use of steel. Easy.