Harry Potter and the Prisoner of Azkaban is a subtheme of the Harry Potter theme released to coincide with the 2004 movie, The Prisoner of Azkaban. 12 sets in all were released.
2011 LEGO Sets
For collectors, 2011 was a significant year in that LEGO released the first Internal sets Moulding Machines (4000001) and LOM 2011 Moulding (4000002) which have paved the way for high value future collections. A few notable themes introduced in 2011 were Ninjago, Winnie the Pooh, SpongeBob SquarePants, Alien Conquest and LEGO Master Builder Academy. Of course LEGO Ninjago set the stages for a decade of collecting. However, in 2011 LEGO also discontinued a number of themes which included Ben 10, Power Miners, Toy Story, Prince of Persia, Space Police III, BrickMaster and the loved Trains theme.