Sixth year

Students attending Hogwarts in their sixth year can expect many changes from how they did things in previous years. One of the major changes that sixth years are most excited about initially is the addition of free time. The free time is, of course, to help the students do homework and study owing to the fact that they have started their N.E.W.T. level classes. Many, if not all the teachers assign more homework, and give more difficult lessons in their N.E.W.T. level classes.

Harry Potter's sixth year (1996)
Harry Potter had a turbulent sixth year. He started dating Ron Weasley's younger sister, Ginny Weasley. The couple spent increasingly less time together, as Harry began his N.E.W.T. level classes, and Ginny began her O.W.L.s.

Ron Weasley also began dating fellow Gryffindor, Lavender Brown, after Ginny told him he was jealous of her reltionships because he had never kissed anyone. Much to Hermione's annoyance, Ron and Lavender became inseperable, and seemed to spend every moment together kissing.

Dumbledore's death
During his sixth year, Harry became increasingly suspicious around Draco Malfoy, starting when he followed Draco down Knockturn Alley. Harry tried to convince Hermione and Ron that Draco had replaced his father as a Death Eater, but they doubted whether Voldemort would allow an underage, inexperienced wizard to serve him.

However, Harry's suspicions turned out to be right. On the night of Dumbledore's death, when Dumbledore took Harry to find another Horcrux, they got back to find the Dark Mark set over the Astronomy Tower. They went up immediately, but as soon as they arrived, they were joined by Draco, Fenrir Greyback, Amycus and Alecto Carrow, and Potions Master Severus Snape.

Draco explained how he had got the Death Eater's into Hogwarts using the Vanishing Cabinet, and when he was unable to kill Dumbledore, Severus Snape cast the Killing Curse, and killed the Headmaster of Hogwarts.