Tiuri is a fictional character from the Dutch children's book series "The Letter for the King," written by Tonke Dragt. He is a young squire who embarks on a quest to deliver an important message to the king, facing various challenges along the way. The story, first published in 1962, has been translated into multiple languages and adapted into films and stage productions. Tiuri's journey highlights themes of bravery, friendship, and the importance of fulfilling one's duty, making it a beloved tale for readers of all ages.