This is how you’d be rewarded if you became a colonial war hero: You’d get Hyde Park as a backyard. In 1815, Arthur Wellesley defeated Napoleon and became the Duke of Wellington, and later prime minister. The mansion, still in the family (they maintain private rooms), was filled with splendid thank-you gifts showered upon him by grateful nations, including a thousand-piece silver set from the Portuguese court. Still, he never seemed to get his nemesis off his mind: Under the grand staircase stands a colossal nude statue of Napoleon that the little emperor despised; the Duke cherished it as a token of victory. Apsley’s supreme art stash, which was largely looted by the French from the Spanish royal family and never went home, includes a few Jan Bruegel the Elders, Diego Velasquez’s virtuosic The Waterseller of Seville (you can understand why it was the artist’s favorite work—just looking at it makes you thirsty); and Correggio’s The Agony in the Garden, in a case fitted with a keyhole so the Duke could open it and polish it with a silk hankie. The Duke and his best friend lived here together after their wives died, and the whiff of faded masculine glory pervades the place like cigar smoke. In other circumstances, the Duke and Napoleon, who both liked fancy finery and fancier egos, would have been buddies. If you’re also visiting Wellington Arch, a joint ticket will save a couple of pounds.