Grenz infantry or Grenzers or Granichary were light infantry troops who came from the Military Frontier in the Habsburg monarchy. This borderland formed a buffer zone between Christian Europe and the Ottoman Empire, and the troops were originally raised to defend their homelands against the Ottoman Turks. When there was no danger of war against the Ottomans, the Grenzer regiments were employed by the Habsburgs in other theatres of war, although one battalion of each regiment would always remain guarding the border.

Light infantry refers to certain types of lightly-equipped infantry throughout history. They have a more mobile or fluid function than other types of infantry, such as heavy infantry or line infantry. Historically, light infantry often fought as scouts, raiders, and skirmishers. These are loose formations that fight ahead of the main army to harass, delay, disrupt supply lines, engage the enemy's own skirmishing forces, and generally "soften up" an enemy before the main battle. Light infantrymen were also often responsible for screening the main body of a military formation.