The Revolutionary Wars

Coignet was conscripted in 1799 and served as a grenadier in the 96th Line. He received a musket of honour for single-handedly capturing an Austrian cannon at the Battle of Montebello. Coignet fought hard at the battle of Marengo, constantly in the thick of the action, in which he and his fellow soldiers had to hold out until French reserves arrived. Coignet survived the battle, and was promoted to the guard and awarded the Légion d'honneur.

The Napoleonic Wars

As a grenadier of the guard Coignet fought at Ulm, Austerlitz, Jena, Eylau and Friedland. He was a witness to negotiations at the Treaty of Tilsit between Napoleon and the Emperor of Russia. After being promoted to corporal he took part in the invasion of Spain and the battle of Somosierra and the pursuit of the British army.

Coignet then fought at Aspern-Essling, in which he and his comrades found themselves under fire from fifty Austrian guns. After victory in the campaign Coignet rose to the rank of sergeant, eventually becoming baggage-master.

Coignet was sent on a series of solo missions for the Emperor during the disastrous invasion of Russia. He took part in an attack on the redoubts during the battle of Borodino. He witnessed the death of general Caulaincourt, whom he accompanied into the fray. Surviving cossacks and the Russian winter, Coignet was a witness to the horrors of the retreat and later on provided a vivid depiction of conditions facing him and his comrades in his memoirs. After the campaign Coignet was promoted to captain in Napoleon's staff.

Coignet participated in the campaigns of 1813-1814 and rejoined the Emperor during the Hundred Days. He was present at Ligny and survived Waterloo. After this he fought and killed a Prussian officer in front of the Prussian lines before Paris.