In the critical days preceding the War of the Sixth Coalition, Bülow kept his troops in hand without committing himself to any irrevocable step until the decision was made. On 14 March 1813 he was made a lieutenant-general. He fought against Oudinot in defence of Berlin, and in the summer came under the command of Bernadotte, crown prince of Sweden.[3]
At the head of an army corps Bülow distinguished himself greatly in the Battle of Grossbeeren, a victory which was attributed almost entirely to his leadership. A little later he won the great victory at the Battle of Dennewitz, which for the second time checked Napoleon's advance on Berlin. This inspired the greatest enthusiasm in Prussia, as being won by mainly Prussian forces, and rendered Bülow's popularity almost equal to that of Blücher.[3]
Bülow's corps played a conspicuous part in the final overthrow of Napoleon at Leipzig, and he was then entrusted with the task of evicting the French from Holland and Belgium. In an almost uniformly successful campaign he won a signal victory at Hoogstraten although he was fortunate to be supported, often very significantly, by the British General Thomas Graham, second in command to Lord Wellington. In the campaign of 1814 he invaded France from the north-west, joined Blücher, and took part in the brilliant victory of Laon in March. He was made general of infantry and received the title of Count Bülow von Dennewitz. He also took part in the Allied sovereigns' visit to England in June 1814.

In the short peace of 1814-1815 Bülow was at Königsberg as commander-in-chief in Prussia proper. He was soon called to the field again, and in the Waterloo Campaign commanded the IV Corps of Blücher's army. He was not present at Ligny, but his corps headed the flank attack upon Napoleon at the Battle of Waterloo, and bore the heaviest part in the fighting of the Prussian troops around Plancenoit. He took part in the invasion of France, but died suddenly on 25 February 1816, a month after his return to the Königsberg command.