單鋒劍

thumb|400px|A type of military backsword – a British 1796 heavy cavalry sword purchased by Sweden in 1808. A backsword is a type of sword characterised by having a single-edged blade and a hilt with a single-handed grip. It is so called because the triangular cross section gives a flat back edge opposite the cutting edge. Later examples often have a "false edge" on the back near the tip, which was in many cases sharpened to make an actual edge and facilitate thrusting attacks. From around the early 14th century, the backsword became the first type of European sword to be fitted with a knuckle