The first thing that happens to Harry Potter and his fellow first-year students when they arrive at Hogwarts is getting sorted into one of four houses: Gryffindor, Hufflepuff, Ravenclaw or Slytherin. It is with some difficulty that the Sorting Hat decided to put Harry in Gryffindor because he also had many traits belonging to those in Slytherin house. We later find out that Hermione, too, gave the Sorting Hat a challenge. She could have just as easily belonged in Ravenclaw as she did in Gryffindor.