Potatoes at the tomb of Frederick the Great.
Frederick the Great, or Frederick II, was also known as the Potato King. He issued orders several times during his reign that the peasants should grow potatoes. These orders are also known as potato orders.
During his reign, some parts of Prussia experienced repeated famines over the years. Frederick the Great saw the cultivation of the potato as a way of countering these.
See also: Frederick the Great (Wikipedia)