Swiss longsword, ca. 1500 (Morges museum)

A longsword, hand and a half sword or bastard sword is a long, symmetrical sword with a cruciform (cross-shaped) hilt, and a double-edged blade tapered to a sharp point for thrusting. Most longswords were made between the mid-14th century and the mid-16th century, and most of these measure approximately 120-150 cm overall (100-120 cm blade length) and weigh an average 1.5 kg.

The term hand and a half sword comes from the sword's design for both single-hand use and double-hand use (usually with the second hand gripping the pommel).

This sword type is ideal for dueling, and its use for this purpose gave rise to both the German and Italian schools of fencing. Longswords appear constantly in the late-medieval German Fechtbücher (combat manuals), and in Western Martial Arts circles these swords are nearly synonymous with early German fencing. The longsword eventually gave rise to lighter weight ring hilted (later swept hilted) swords for single-hand use, called rapiers, which saw extensive use in post-medieval dueling or fencing.