The Landsknechte (singular: Landsknecht, pronounced [ˈlantsknɛçt]), also rendered as Landsknechts or Lansquenets, were German mercenaries used in pike and shot formations during the early modern period. Consisting predominantly of pikemen and supporting foot soldiers, their front line was formed by Doppelsöldner ("double-pay men") renowned for their use of Zweihänder and arquebus. They formed the bulk of the Holy Roman Empire's Imperial Army from the late 15th century to the early 17th century, fighting in the Habsburg-Valois wars, the Habsburg-Ottoman wars, and the European wars of religion.
Although prone to mutiny if unpaid and divided within their ranks between Catholics and Lutherans, the Landsknechte were well-armed and experienced warriors, recruitable in large numbers throughout Germany and Austria by the Holy Roman Emperor. This guaranteed both quantity and quality to the Imperial military for a century and a half. At their peak during the reign of Charles V of Habsburg, and under the leadership of notable captains such as Georg von Frundsberg and Nicholas of Salm, the Imperial Landsknechts obtained important successes such as the capture of the French King Francis I at the Battle of Pavia in 1525 and the resistance against the Ottoman Turks led by Suleiman the Magnificent at the Siege of Vienna in 1529, while also being responsible for the Sack of Rome in 1527.