Visitors to the grave of Frederick the Great at Sanssouci, his palace at Potsdam, leave an odd tribute on the stone slab: potatoes. Not flowers, not flags — potatoes. They are thanking him for a piece of eighteenth-century public policy that arguably did more for Europe than any of his battles. Frederick badgered, bribed and finally ordered his subjects to plant a suspicious foreign tuber, and Prussia learned to survive on it. How the potato went from feared botanical oddity to the continent's staple food is one of history's great marketing stories.
The plant itself is South American, domesticated in the Andes around Lake Titicaca perhaps eight thousand years ago, where farmers bred thousands of varieties and even freeze-dried them into storable chuño. Spanish conquistadors brought it across the Atlantic in the second half of the sixteenth century, and for two centuries Europe barely knew what to do with it. The potato is a nightshade, cousin to deadly poisons, and its green parts genuinely are toxic; it grew from tubers rather than seed, was not mentioned anywhere in the Bible, and came out of the ground misshapen and pale. It was variously blamed for leprosy, flatulence and lust. In France, suspicion ran so deep that the Paris parliament effectively banned its cultivation in 1748 on health grounds. For generations it remained pig feed, prison food and famine insurance for the desperate.
Frederick took a different view. Potatoes yielded reliably in Prussia's sandy soils, and a crop that grew underground could not be burned or trampled by passing armies. From 1756 he issued the so-called Kartoffelbefehl — the potato order — instructing officials to distribute seed potatoes and teach cultivation. The famous embellishment says he planted a royal potato field and posted guards around it, with quiet instructions to be lax at night, reasoning that peasants would ignore anything free but steal anything worth guarding. Historians find no firm evidence for the guarded-field trick — it is best treated as legend — but the order itself is real, and by his death Prussia was a potato country. The tuber even lent its name to a conflict: the War of the Bavarian Succession (1778–79), in which Prussian and Austrian armies spent more energy eating and denying each other supplies than fighting, is remembered in German as the Kartoffelkrieg — the Potato War.
The pharmacist's dinner parties
France needed a showman, and got one in Antoine-Augustin Parmentier, an army pharmacist captured by the Prussians during the Seven Years' War and fed almost nothing but potatoes in captivity. Emerging healthy, he made the tuber his life's cause. He won an academic prize with an essay proposing potatoes as famine food, and then ran what we would now call a publicity campaign: elegant dinners at which every course was potato-based, with guests such as Benjamin Franklin and the chemist Lavoisier; bouquets of potato flowers presented to Louis XVI and Marie Antoinette, who reportedly wore the blossoms at court; and, borrowing Frederick's playbook, a potato plot at Sablons near Paris conspicuously guarded by day and left unguarded at night, inviting theft. The ban had crumbled, fashion followed, and French menus still honour him — anything parmentier means it comes with potatoes.
The stakes were larger than fashion. An acre of potatoes yields far more food energy than an acre of grain, tolerates poor soil, and pairs neatly with a little milk to make a survivable diet. As cultivation spread through the eighteenth and nineteenth centuries, famines thinned and populations surged; one influential modern study credits the potato with roughly a quarter of the Old World's population growth between 1700 and 1900. Armies marched on it, cities industrialised on it, and northern Europe's demographic explosion was, to a startling degree, fried, boiled and mashed.
The triumph had a dark coda. Nowhere embraced the potato as completely as Ireland, where by the 1840s a large share of the population lived almost entirely on a single high-yielding variety, the lumper. When the blight Phytophthora infestans arrived in 1845 and rotted the crop in the ground year after year, there was nothing beneath the safety net: roughly a million people died and well over a million emigrated, and Ireland's population has never returned to its pre-famine peak. The tuber that ended hunger across a continent also taught the cruellest lesson in the danger of depending on one plant. Europe's cheapest food turned out to carry the highest stakes of all.
Quiz nuggets
- The potato was domesticated in the Andes near Lake Titicaca, and reached Europe with the Spanish in the sixteenth century.
- The Paris parliament effectively banned potato cultivation in 1748; the pharmacist Antoine-Augustin Parmentier later championed the crop.
- Frederick the Great's Kartoffelbefehl (potato order) of 1756 pushed potato planting across Prussia — visitors still leave potatoes on his grave.
- Dishes styled "parmentier" contain potato, honouring the man who gave potato-flower bouquets to Marie Antoinette.
- The Irish famine began in 1845 when Phytophthora infestans blight destroyed the potato crop; about a million people died.