In 1809 the regiment was transferred to Prince Eugene's Army of Italy and took part in the defeat at Sacile and the victory on the Piave River but gained everlasting fame for its actions at the Battle of Graz on the 25th of June.

After 17 hours of fighting against a far superior force, the situation was desperate but the rest of Boussier's Division arrived just in the nick of time saving them.

It was on the battlefield of Wagram that he presented the Emperor with the flags taken at Gratz: "Colonel," said Napoleon, "I am pleased with the bravery of your regiment and yours, you will have your eagles engraved: ONE AGAINST TEN.

The 84th regiment also received 96 decorations of the Legion of Honor and an imperial decree of August 15 conferred on the colonel the title of count, with an endowment of 10,000 francs of annuity.

It was the first to suffer the German assault from the 7th Panzer Division which broke through to Clairfayts before retreating with the remains of the 87th Fortress Infantry Regiment in the SF Escaut.