Seven Years%27 War
The Saxon and Austrian armies were unprepared, and their forces were scattered. Frederick occupied Dresden with little or no opposition from the Saxons. At the Battle of Lobositz on 1 October 1756, Frederick prevented the isolated Saxon army from being reinforced by an Austrian army under General Browne. The Prussians then occupied Saxony; after the Siege of Pirna, the Saxon army surrendered in October 1756, and was forcibly incorporated into the Prussian army. The attack on neutral Saxony caused outrage across Europe and led to the strengthening of the anti-Prussian coalition. The only significant Austrian success was the partial occupation of Silesia. Far from being easy, Frederick's early successes proved indecisive and very costly for Prussia's smaller army. This led him to remark that he did not fight the same Austrians as he had during the previous war.

Q: What happened to the Saxon army?
Saxon army surrendered in October 1756, and was forcibly incorporated into the Prussian army