Draco Dormiens

Draco Dormiens is the first installment of The Draco Trilogy by Cassandra Claire. Since it was written before Harry Potter and the Order of the Phoenix and set after it, it is now an alternate universe fic. It was very influential in the early days of the fandom, but became controversial when it was found that parts of it were plagiarized.
It was followed by Draco Sinister and Draco Veritas. Cassandra Claire removed the whole series from the Internet after she became a published author.