What does the phrase “upside down” mean and Where does it come from?

Strangely enough, we have had the expression “upside down” only since the time of Queen Elizabeth.

Before that, when one wanted to say that a thing was overturned or in a state of disorder, he said it was “upsedown,” or, with the same meaning, “topsy-turvy.”

From a variety of evidence, the early form of upsedown was up so down, but nothing has yet been found that would explain this Old English usage, nor, indeed, explain the source of “topsy-turvy.”