Wikipedia
The (a non-historical modern popular term, German term for "two hander", for the more accurate Doppelhänder ("double-hander") or Beidhänder ("both-hander")) is a type of large two-handed sword primarily in use during the early decades of the 16th century.
The Zweihänder swords develop from the bastard sword or montante ("longsword") of the Late Middle Ages and they became a hallmark weapon of the German Landsknechte from the time of Maximilian I (d. 1519) and during the Italian Wars of 1494–1559. The Goliath Fechtbuch (1510) shows an intermediate form between longsword and Zweihänder.
These swords represent the final stage in the trend of increasing size that started in the 14th century. In its developed form, the Zweihänder has acquired the characteristics of a polearm rather than a sword . Consequently, it is not carried in a sheath but across the shoulder like a halberd.
By the second half of the 16th century, these swords had largely ceased to have a practical application, but they continued to see ceremonial or representative use well into the 17th century. Some ceremonial zweihänder, called "bearing-swords" or "parade-swords" (Paradeschwert) were much larger and weighed about .