In fact, there was an “Old Ironsides” before Constitution, and she was British.
The Battle of Trafalgar (Oct. 21, 1805), was a massive engagement between a Royal Navy fleet under the command of Admiral Horatio Nelson and the combined Spanish and French fleets under Admiral Pierre-Charles Villeneuve. In an 1806 account of the battle we read about HMS Britannia’s role in the fight:
The Britannia (Old Ironsides, as our brave sailors call her) certainly did no discredit to the name she bears…
A slightly later account of the battle repeats the name:
The Earl of Northesk, who was third in command, greatly distinguished himself on this memorable day. His ship, the Britannia, (which was facetiously called by the sailors Old Ironsides,) broke through the enemy's line, a-stern of the fourteenth ship.
This Britannia was the third ship of the name to serve in the Royal Navy. A first-rate ship-of-the-line mounting 100 guns, she was launched at Portsmouth, England in 1762. She sailed to the relief of Gibraltar (when besieged by the Spanish) in 1782. She fought at the Battle of Cape St. Vincent in 1797. Placed back in commission in 1803, she served as the flagship of William Carnegie, 7th Earl of Northesk at Trafalgar.
|Sheer plan and half-breadth of HMS Britannia (1762)- the first "Old Ironsides." National Maritime Museum, Greenwich, England.|
We don't know if there was a pivitol moment in the heat of some battle during which Britannia became "Old Ironsides." She was a massively strong and heavily-built ship, and quite aged by 1805. These traits alone could have made her into "Ironsides."
According to the ship’s muster rolls, there were eighteen Americans serving in Britannia’s crew in October 1805. And according to Guerriere’s Lt. Bartholomew Kent, at least seventeen of Constitution’s gun captains had served in the British fleet at the Battle of Trafalgar. Could one of these men have served on HMS Britannia, and applied his former ship’s nickname to his new one? If so, it is fitting he did so on the very day when Britannia no longer (entirely) ruled the waves.
 Archibald Duncan, The British Trident; or, Register of Naval Actions, Vol. V (London: James Cundee, 1806), 43.
 John James M’Gregor, History of the French Revolution, and of the Wars Resulting from that Memorable Event, Vol. VIII (London: G.B. Whittaker, 1828), 93-94.
 Proceedings of the United States Naval Institute, Vol XXI, No. 113 (Baltimore: Lord Baltimore Press, 1905), 210.
 Edward Fraser, Champions of the Fleet, Captains and Men-of-War and Days that Helped to Make the Empire (London: John Lane, 1908), 283.
 “Record of the Court Martial of Captain James Richard Dacres, Jr., Late Commander of HMS Guerriere,” Public Records Office, ADM 1/5431.