Bastard-sword or hand-and-a-half sword are modern terms for several varieties of straight-bladed European swords that can be wielded in one or two hands. The contemporary term used in the German school of swordsmanship was langes schwert "long sword", and Spadone in Italy. The term bastard-sword retrospectively views these swords as a compromise between the one-handed knightly sword of the High Middle Ages, and large two-handed zweihanders of the 16th century. The bastard-sword appeared in virtually all West European countries after 1300 AD and remained in use well into the 1500s. Most specimens are not actually desigend to be wielded with one hand, this impression probably arose in comparison with the enormous zweihander swords. To the contrary, there is evidence that regular 13th century knightly swords were occasionally used two-handed, when the fighter's shield had become useless, or in the final stages of a fight, when he was too tired for continue one-handed use.

All 15th century fechtbucher teaching use of the langes schwert show two-handed use, either with both hands on the grip, or in half-sword, with the left hand gripping the center of the blade, in combat in plate armour.

Use of these swords declined in the late 16th century, and they became obsolete in the 17th century.

Late medieval long-sword combat

While a living tradition of long-sword fighting has not survived to our day, manuscripts written by the masters of the art still exist. Among the most famous of these treatises are Fiore dei Liberi's "Flos Duellatorum" (1410) and Filippo Vadi's "De Arte Gladiatoria Dimicandi" (1485), of the Italian school, and Hans Talhoffer's "Alte Armatur und Ringkunst" (1459) and Ms. 3227a (ca. 1389, containing the system of Johannes Liechtenauer), of the German school. In recent decades, efforts to revive the art by translating and analyzing these treatises have been made throughout Europe and North America, leading to a much deeper knowledge base about the nature of European swordsmanship.