Prussia was a German state in northern Europe, not a country you can visit now. From the 1600s to the 1800s it was famous for a strong army and a stiff, ordered way of running things. It grew and grew, and in the 1800s it was Prussia that pulled many German lands into one Germany. After the Second World War the name was taken off the map, and the land was split among Germany, Poland, and the Soviet Union. So when a book says “in Prussia,” it is pointing at that old state, or at that stretch of coast by the Baltic Sea, not at a place on today’s school map. Though actually, the name did not start as a German word. New Latin Prussia was a Latin way of writing a name a Baltic people used for themselves — Old Prussian, or perhaps Lithuanian or Latvian. In those languages the u sound is long. We do not know for sure what the name first meant. Some scholars point to old words for splashing and sprinkling, and they suggest “watery land,” but that is a guess, not a fact. Middle English called the place Pruce, and that old name is where the English words pruce and spruce come from.