He is best known for his consummate actions whilst commanding the tenth brigade during the Battle of Waterloo, which kept open the vital line of communication between Hougoumont farmhouse and the rest of the Allied army.

He served in Portugal and Spain in 1808, and was present at Corunna, and he commanded the light companies of the guards in the Walcheren expedition of 1809.

[1] Having been sent to America, he joined the army under Sir Edward Pakenham, at the Battle of New Orleans, on 6 January 1815, with the 7th and 43rd regiments.

Pakenham being killed, and General Gibbs mortally wounded, the chief command devolved on Lambert.

He proceeded to Mobile Bay, where Fort Bowyer was taken on 12 February, and next day news arrived that a peace treaty had been signed.

[1] Lambert returned to Europe in time to command the tenth brigade of British infantry at the Battle of Waterloo.

One battalion was deployed in square at the point where the Ohain road crossed the Charleroi to Brussels highway.

At a range of 300 yards (270 m), the French artillery caused the unit enormous casualties within a short time.