Who is the person known as the 'Iron Duke' who triumphed over Napoleon?

The 'Iron Duke' nickname refers to Arthur Wellesley, the 1st Duke of Wellington, a prominent figure in British military history. Wellington earned this moniker due to his stern discipline, unflinching resolve, and, some say, because he installed iron shutters at his London home to deter rioters! His most famous victory was undoubtedly at the Battle of Waterloo in 1815, where he decisively defeated Napoleon Bonaparte, ending Napoleon's reign and reshaping European politics. While Admiral Nelson was a brilliant naval commander who defeated Napoleon's forces at sea, most famously at the Battle of Trafalgar, he wasn't involved in the land-based Waterloo battle. Churchill, of course, was a key leader, but much later, during the Second World War. Sir Christopher Wren was a famous architect, responsible for rebuilding many London churches after the Great Fire, including St. Paul's Cathedral, but he had no military connection to Napoleon. Therefore, Wellington is the only figure listed who fits the description of the 'Iron Duke' who triumphed over Napoleon.