Napoleon's final victory at Ligny failed to knock the Prussians out of the war

On June 16, 1815, Napoleon Bonaparte secured his last military triumph at Ligny, defeating a Prussian army under Field Marshal Blücher. Yet, the victory was incomplete. By failing to destroy the Prussian force, Napoleon left them capable of regrouping and joining Wellington at Waterloo just two days later.

Following his return from exile, Napoleon faced a coalition of powers determined to end his rule. To survive, he aimed to strike before the British and Prussians could unite. His strategy relied on a classic maneuver: dividing the two armies and defeating them in detail. By crossing the frontier at Thuin on June 15, he positioned his forces between Wellington to the north-west and Blücher to the north-east.

The battle at Ligny began in earnest on June 16, with Napoleon attacking the Prussian defensive line centered on the villages of Ligny, Saint-Amand, and Wagnelée. The fighting was brutal and close-quarters, with the French eventually overwhelming the Prussian center using the Old Guard and heavy cavalry. During the chaos, the 72-year-old Blücher was pinned under his fallen horse and had to be carried from the field, leaving command to his chief of staff, Lieutenant General Gneisenau.

Despite the tactical defeat, the Prussian army remained largely intact. A critical miscommunication involving Marshal Ney and the movement of d'Erlon's I Corps meant that French forces were not fully concentrated to exploit the breakthrough. The Prussians retreated in good order to a new defensive line, allowing them to reinforce Wellington at the Battle of Waterloo on June 18. This failure to decisively neutralize the Prussians ensured that Ligny would be the final victory of Napoleon's career.

Source: Battle of Ligny