In which European country have the oldest Longbow remains been found?

Answer 1

Unfortunately, there isn't a single clear answer to this question, because the definition of "longbow" is debatable. If you're calling something a longbow based on relative length alone, then the current oldest bow in the world is from Denmark, where a group of bows called the Holmegaard bows were found in peat bog near a town of the same name. They are nearly six feet long and about 7000 years old.