Recorded in amy forms including Kos, Kose, and Kosel, this very interesting surname is Mid European. It is mainly recorded in Germanic areas such as Germany itself, Austria and the now Czech Republic. It has two possible origins. The first is from an ancient word of the pre 10th century, 'kos', meaning blackbird. In medieval times the blackbird had a quite undeserved reputation for being cunning or even devilish, and it is claimed that this word was then used in a transferred sense for a person who was a merchant or trader. It has to be said that trying to ascribe precise meanings to surnames created sometimes eight hundred years or more ago, is at best a rsiky occupation. In our view the original meaning is open to conjecture, but logic suggests that had it really implied dishonesty, it could hardly have survived all these years. There is a secondary possible meaning in that the origin could be, at least for some nameholders, from the Yiddish word 'kos' meaning a cup or glass, and hence a name for a maker or seller of these wares. The surname is one of the first to be recorded in the early German registers, which are much the earliest on the continent. These include Hermann Kosele of the city of Worms in 1321, and Heinrich Kos of Aufkirch, Uberlingen, Germany, in 1366.