Following the outbreak of hostilities over the control of Silesia once again, the Third Silesian War broke out, which would become part of the larger Seven Years' War, itself making a profound impact on the future of the world as a whole. In 1756, the regiment joined in the blockade of the Royal Saxon Army in Pirna while the main Prussian field army was engaged against the Austrians at the Battle of Lobositz (1 October). On 6 May 1757, the regiment lost two third of its strength (22 officers and 1,168 men) during the failed Siege of Prague. At the end of August, the regiment was part of the small Prussian army hastily assembled at Dresden to oppose the Franco-Imperial Army invading Saxony. The regiment then fought at the Battle of Rossbach (5 November), Battle of Leuthen (5 December), and finally the Siege of Breslau (7-20 December).