Complex sentence: Many armies contained other light troops other than the officially designated'light infantry' which fought as dedicated skirmisher units ahead of the main force, such as the French Voltigeurs or the German Jäger.
Split into simpler sentences: Many armies contained other light troops other than the officially designated'light infantry'. These units fought as dedicated skirmisher units ahead of the main force, such as the French Voltigeurs or the German Jäger.