Bisinus (sometimes shortened to Bisin) was the king of Thuringia in the 5th century AD or around 500. He is the earliest historically attested ruler of the Thuringians. Almost nothing more about him can be said with certainty, including whether all the variations on his name in the sources refer to one or two different persons. His name is given as Bysinus, Bessinus or Bissinus in Frankish sources, and as Pissa, Pisen, Fisud or Fisut in Lombard ones.[1]