In the summer of 1946, after sifting through the detritus of the Führerbunker and completing his best-selling book The Last Days of Hitler, the British historian Hugh Trevor-Roper went on a fishing holiday to Iceland.

The pursuit of salmon, trout, and char, he reported to friends in his native Northumberland, was “exhausting.” Having walked eight miles across lava fields in waders, carrying rod, tackle, and a four-pound bull trout, he decided to try an Icelandic pony.

It was a bad idea. The weather was the sort that would have caused Noah to hurry up and finish his ark, and the beast proceeded at a glacial pace toward the river. Finally, after arriving at the water, the historian hobbled the pony and began the Sisyphean task of trying to get a line out against an upstream wind. The story is continued in his letter home:

Just when I reached that familiar stage when the cast was entangled into a quite inextricable cocoon and the flies had hooked themselves in a quite inaccessible part of my mackintosh, I would hear a dull thud to the rear and looking round would see that the pony, attempting surreptitiously to unhobble itself, had looped the loop and was lying on its back among the lava-humps, with its feet in the air, and a dissatisfied expression on its face. After this had happened twice, I tried leaving the pony unhobbled and trusting to its good sense. A fatal confidence! It would wait till my back was turned, and then wander away at a speed which it had never shown on any other occasion. Altogether, I think it is easier to fish without a pony.

The author tried British historian Hugh Trevor-Roper’s pony trick, to similar end.

How things change. Alas, the time when eccentric Englishmen could just turn up and, on a historian’s salary, start flogging Icelandic rivers is long gone.

Salmon fishing in Iceland is now big business, a luxury affordable only to the very rich. (I was there at the munificence of an extremely generous friend.) Parties fly into Reykjavík on private jets, take helicopters to the topmost beats, stay in sumptuous lodges, and are fed by Michelin-starred chefs. And that is the cheap part!

To fish one rod on one of the top rivers in Iceland costs north of $10,000 per week. As the 2008 financial crisis demonstrated, Icelanders, for centuries farmers and fishermen, have become some of the most rapacious capitalists in the world.

The time when eccentric Englishmen could just turn up and, on a historian’s salary, start flogging Icelandic rivers is long gone.

So what is all the fuss about? What is it about fishing in Iceland that persuades hedge-fund managers, rock stars (Eric Clapton fishes the Vatnsdalsá River every summer), former presidents (George Bush Sr. caught nine fish on the Selá), businessmen (the chemicals giant Jim Ratcliffe has spent a reported $49 million buying land and fishing rights in the country), and royalty (for years Prince Charles fished the Hofsá) to part with so much cash?

Eric Clapton in 2016, holding the biggest salmon caught in Icelandic rivers that summer.

To a large extent it is supply and demand. Thanks to industrial salmon farms—which spread parasites and disease to the wild population—climate change, and the unchecked proliferation of predators such as seals, wild-Atlantic-salmon numbers have declined by a terrifying 70 percent in the last 25 years. Renowned Scottish rivers—once the envy of fishermen the world over—are increasingly hit-and-miss, while the number of places in England where one can be confident of catching a salmon may be counted on one hand.

These are the adverse factors propelling fishermen toward an island that may contain only 350,000 people but has more premier salmon rivers than anywhere else in the world. But there is also the magic of Iceland itself.

Known as the Land of Fire and Ice, Iceland features a prehistoric landscape of dazzling fjords, lush pastures, and live volcanos. An ornithologist’s paradise, its gin-clear waters—often in deep canyons, beneath foaming waterfalls—and stream of silverfish are more than enough to persuade anglers from Britain, Europe, and the U.S. to pony up and make the not inconsiderable journey and considerable financial sacrifice, often for just a few days of fishing.

The author puts the lessons of an 11-year-old to the test.

The sport is technical—micro-flies emanating from small rods at the end of translucent lines that should barely caress the water—but all the more enjoyable for the challenge. Although our host was tragically kept from joining us by a business meeting, his 11-year-old son was deputized in his stead, caught his first salmon, and soon was offering fishing tips to the rest of the party.

Icelanders, for centuries farmers and fishermen, have become some of the most rapacious capitalists in the world.

Fortunate to spend two days with this delightfully cheeky chap on the Thverá River, in western Iceland, our only point of disagreement came when, out of the mist, a guide appeared leading two Icelandic ponies.

My young companion refused so uncomfortable a mode of transport, forcing me to ride what felt like an oversize Labrador (in waders), on my own, up to the top pool. Against an upstream gale and with rain trickling down my neck, I struggled to make headway while my friend ate Maryland cookies in the car. He then purred down to the bottom pool, made a couple of nonchalant casts, and caught an eight-pound salmon!

Forget polo; let thoughts of peacocking in top hat or fascinator at Royal Ascot evaporate from your mind: salmon fishing in Iceland is the real sport of kings and, as my 11-year-old friend proved, the pony is optional.

Tim Bouverie is a U.K.-based historian and the author of Appeasement: Chamberlain, Hitler, Churchill, and the Road to War