On 16 March, the same day that St.-Marsan received official news of the Russo-Prussian alliance along with Frederick William's declaration of war, the vanguard of Blücher's II Corps struck the road to Dresden. The remaining troops followed on the 17th, with the exception of Colonel Friedrich Erhard von Röder's Brandenburg Brigade. Frederick William wanted the Brandenburgers to remain at Breslau due to the presence of Poniatowski's Poles at Tarnowitz, 100 miles southeast of Breslau. However, on Scharnhorst's orders, the brigade followed II Corps on the 24th after Poniatowski continued his forced retreat to Austria. Frederick William would not forget this affront.

With Scharnhorst serving as chief, Blücher's staff represented the very pinnacle of Prussian military thinking and may well have been the greatest staff of all time in terms of intellect, acumen, and collective experience. Majors Karl Wilhelm von Grolman, Johann Wilhelm von Krauseneck, and Otto August Rühle von Lilienstern, joined later by Lieutenant-Colonel Karl Ferdinand von Müffling – all future Chiefs of the General Staff of the Prussian Army – as well as many other majors, captains, and lieutenants, assisted Scharnhorst. Clausewitz, who remained in the tsar's service, accompanied the staff as the Russian liaison. In addition, Prince August, the king's cousin, accompanied headquarters as General Inspector of the Artillery. The seventeen-year-old crown prince, affectionately called “Fritz,” the king's brother, Prince William, the king's nephew, Prince Frederick (son of Frederick William's brother, Louis), and the king's brother-in-law, Prince Karl of Mecklenburg-Strelitz, all joined Blücher to earn their spurs. Frederick William remained with the tsar throughout the war.