Dumledore’s army was a secret organisation. During year 5, the appointed DADA teacher was Dolores Umbridge. Due to her appointment being made by the ministry, she was teaching in a way that was lame as a result of the Minister being afraid that Dumbledore was training Hogwarts pupils to form an army. Everybody shared the same feeling that without help, they would all fail as mere theoretical magic alone was useless. Thanks to more of Hermione’s genius, Harry was persuaded to lead and teach the clan the practical side of DADA. This proved helpful as during the exams everyone did well and Umbridge was unhappy with the fact they did well.
The club was initially formed as a homework club. The first meeting was at the ‘Hogs Head’ where they all signed a piece of parchment agreeing not to tell anyone about themselves. Umbridge however was infuriated by this action and as such created ‘Educational Decree Number Twenty Four’ which made the club ‘illegal’ unless they sought permission from Umbridge. Obviously they carried on behind her back but were no longer a homework club and as such needed a name.
As the club was now ‘officially’ disbanded but still ‘unofficially’ active, they had to meet in secret. This meant that they could not meet anywhere where they could be detected, spied upon or caught. Even Hermione was unable to think of somewhere suitable however Dobby was and suggested ‘The Room of Requirement’. This room is magical in every sense and was perfect for the needs of the DA. By asking for ‘somewhere to fight ... somewhere to practise … somewhere they can’t find us’ (OOTP, 345) a door appeared to their new DADA room.
”It was a spacious room lit with flickering torches like those that illuminated the dungeons eight floor below. The walls were lined with wooden bookcases and instead of chairs there were large silk cushions on the floor. A set of shelves at the far end of the room carried a large range of instruments such as Sneakascopes, Secrecy Sensors and a large, cracked Foe-Glass …”
The amount of books was also enough to convince Hermione that this was a good idea!
During the first meeting Hermione suggested choosing a leader. Everyone voted Harry. Next on Hermione’s agenda was a name. Suggested names were “The Anti-Umbridge League” by Angelina and “The Ministry of magic are Morons Group” by Fred. Cho Chang suggested the ‘DA’ but with it being an abbreviation for the ‘Defence Association’. It was Ginny who came up ‘Dumbledore’s Army’, purely to irritate Umbridge more if she was ever to find out.
During the time of the DA, one member turned traitor. Marietta Edgecombe, Cho’s friend decided to tell Umbridge of Potter’s antics and of the existence of the DA. Umbridge used her ‘Inquisterial squad’ to help trap the members though this failed, the member list was found shortly afterwards which meant the previous failure to catch everyone was forgotten. This listed all the members of the DA and helped Umbridge in knowing who was taking part.
The piece of parchment was much more though. Hermione had also placed a snitch jinx on it so that anyone who had signed and told anyone about the club they would suddenly grow “… a series of close-set purple pustules that had spread across her nose and cheeks to form the word ‘SNEAK’”. This is either an invention of Hermione’s, or at least a modification of an existing jinx.
What Marietta had said though was worth less than it seemed. Umbridge accused Potter of forming an illegal club at the Hogs Head. Dumbledore soon pointed out that at the time, it was perfectly legal. Umbridge then carried on to say that all the meetings since had been illegal. Thanks to some ingenuity from Kingly who was also present, Marietta’s mind was swept so she said there had no more meetings.
The piece of parchment also had the groups name on though “Dumbledore’s Army”. Before Fudge could make anything of it Dumbledore claimed the group was setup by him and that he was forming an army against the Ministry, all to protect Potter.
Communication is important in any sort of group of people. Hermione, again quick to be the one thinking about this sort of thing, devised a safe method for this. It involved the members using a fake golden galleon. With her ‘unique for her age’ ability, she was able to perform a ‘proteus’ charm on the coins. This meant that when one was changed, they would all change. When communication was therefore required, Hermione would change her coin to display the date and time and as a result they would all show the same. This idea was based on the Death Eaters form of communication via their ‘Dark Marks’.
Some members of Dumbledore’s Army (ie. The trio, Ginny, Luna and Neville) also took part in a large death eater fight in ‘OOTP’. Harry had been seeing ‘visions’ of a mysterious room which was in the MOM. One day (during an exam!) he saw Sirius there in pain being tortured. Ron and Hermione convinced him to try and figure out if he actually was there first. He therefore tried to gain access to Umbridge’s office as her fireplace was the only unmonitored one. The others stood watch waiting to give warning if anyone was coming. Well they got caught but managed to escape when Hermione led herself Harry and Umbridge into the forest away from the others. Umbridge managed to seriously offend the centaurs which later took her with them. Harry and Hermione were saved from the same fate by Gwarp. During this little escapade, Ron, Ginny, Neville and Luna had managed to free themselves from the members of the Inquisterial squad who were ‘holding’ them (literally and quite tight). Luna came up with the idea to travel using thestrals. This proved hard for those who couldn’t see them. When they got to the ministry they proceeded to the department of mysteries following where Harry had gone in his vision/dream (?). When they found that Sirius wasn’t there and Harry had picked up the prophecy, the death eaters surrounded them. Harry talked keeping them busy while he came up with a plan as they couldn’t just fight because they were outnumbered 2 to 1. They all shouted ‘reducto’ and knocked the large shelves over and smashed lots of small glass spheres while running away. Conflict started immediately with Harry elbowing one of them, another grabbing hold of him and Hermione stupefying him to loosen his grip enabling Harry to carry on. They all got separated and Neville managed to disarm both an enemy death eater and Harry after Harry had stupefied the other. Neville then tried to stupefy the death eater he just disarmed but missed smashing all the hourglasses. Hermione them stupefies the same death eater who falls into the bell jar and his head keeps shrinking into a baby head then growing back. Next 2 death eaters corner Harry, Hermione and Neville in another room. They impedamenta the three of them and Hermione smashes into a bookcase while Neville disappeared from Harry’s view and Harry’s head was smashed into a stone wall. Acting quickly as usual Hermione silences one death eater who tries to shout to the others then Harry used the ‘petrificus totalus’ spell on the other. Unfortunately spells don’t have to be said aloud to be performed as the silenced death eater shows on Hermione who lay motionless after a streak of purple flame passed her
In 'The Half-Blood Prince', the club is disbanded as the need for such a club was eradicated due to the removal of Umbridge and the addition of Snape. Whether the members all kept their coins or not is unknown though we know that at least some of them did and checked them regularly. These were Neville and Luna.
Before Harry and Dumbledore’s outing to ‘the cave’, Harry told Hermione to rustle up as many from the DA as she could (HBP, 515). From everyone only Neville and Luna responded.