On March 24th, 1756, ๐—ž๐—ถ๐—ป๐—ด ๐—™๐—ฟ๐—ถ๐—ฒ๐—ฑ๐—ฟ๐—ถ๐—ฐ๐—ต ๐—œ๐—œ ๐—ผ๐—ณ ๐—ฃ๐—ฟ๐˜‚๐˜€๐˜€๐—ถ๐—ฎ (Frederick II, Friedrich der GroรŸe or Der Alte Fritz) announced in Silesia that farmers should start planting potatoes. This decree is called "๐—ž๐—ฎ๐—ฟ๐˜๐—ผ๐—ณ๐—ณ๐—ฒ๐—น๐—ฏ๐—ฒ๐—ณ๐—ฒ๐—ต๐—น" or "๐—ž๐—ฎ๐—ฟ๐˜๐—ผ๐—ณ๐—ณ๐—ฒ๐—น๐—ฒ๐—ฟ๐—น๐—ฎ๐˜€๐˜€" (potato order, edict).
Ten years before a similar decree was issued to the people of Pomerania because of a famine. Altogether, there were probably around 15 different ๐—ž๐—ฎ๐—ฟ๐˜๐—ผ๐—ณ๐—ณ๐—ฒ๐—น๐—ฏ๐—ฒ๐—ณ๐—ฒ๐—ต๐—น๐—ฒ.
It took a while before the potato became the staple of German cuisine as it is now. Mostly because it wasn't clear to the people which part of the potato was to be eaten and how exactly to grow it.
But nowadays, you can't imagine Germany without all kinds of forms of potatoes: potato salad, fried potatoes (๐—•๐—ฟ๐—ฎ๐˜๐—ธ๐—ฎ๐—ฟ๐˜๐—ผ๐—ณ๐—ณ๐—ฒ๐—น๐—ป), potato pancakes (๐—ž๐—ฎ๐—ฟ๐˜๐—ผ๐—ณ๐—ณ๐—ฒ๐—น๐—ฝ๐˜‚๐—ณ๐—ณ๐—ฒ๐—ฟ), potato dumplings, french fries (with mayo), salted potatoes (๐—ฆ๐—ฎ๐—น๐˜‡๐—ธ๐—ฎ๐—ฟ๐˜๐—ผ๐—ณ๐—ณ๐—ฒ๐—น๐—ป), boiled potatoes (๐—ฃ๐—ฒ๐—น๐—น๐—ธ๐—ฎ๐—ฟ๐˜๐—ผ๐—ณ๐—ณ๐—ฒ๐—น๐—ป, preferably with herring in a creamy sauce), potato au gratin (๐—ž๐—ฎ๐—ฟ๐˜๐—ผ๐—ณ๐—ณ๐—ฒ๐—น๐—ด๐—ฟ๐—ฎ๐˜๐—ถ๐—ป) and mashed potatoes. And probably a couple of regional varieties that I either forgot or don't know about.
What's your favorite potato dish?

Photo: Friedrich II. inspiziert auf einer seiner Inspektionsreisen den Kartoffelanbau (โ€žDer Kรถnig รผberallโ€œ, Gemรคlde von Robert Warthmรผller, 1886). Frederick inspects the potato cultivation ("The King everywhere", painting by Robert Warthmรผller, 1886), public domain.