The Minister for Magic is the leader of the wizarding world in the United Kingdom and the highest ranking member of the Ministry of Magic, which they control. The position somewhat corresponds to the Prime Minister of BritishMuggles.
The Minister is advised on wizarding matters by their staff members and by the other Heads of Departments. They also chair the Wizengamot to pass Wizarding Laws, or to hear important trials (such as Harry Potter's case), though the verdict is decided by a panel of jury, including the Minister themselves. Many other wizarding countries also have Ministers and have the similar governmental systems such as the Bulgarian minister.
Despite being the head of the wizarding community of Britain, the Minister would nevertheless be pressured by the public and media alike, as the previous two Ministers of the more current times were pressed to maintain a facade of peace and control to satisfy the citizens, even if it means to lie through their teeth. This is a sign of corruption during the times of the Second Wizarding War, as well as only with irrefutable evidence would they reveal as little as they could.
Albus Dumbledore was offered, but refused, the position on at least three occasions. This was due to Dumbledore's past, leading him to believe that he was not to be trusted with power.
After Millicent Bagnold was preparing to retire, Barty Crouch Sr. was the next prime candidate, due to his cruel but effective methods of combating the Dark Arts during the First Wizarding War, until he sentenced his son to Azkaban for being a Death Eater. It was after his son's presumed death that the public began to take pity on the boy and thought Crouch was too neglectful as a father, which led to a drop in his popularity, causing him to lose out to Fudge.
Cornelius Fudge was Minister from 1990 to 1996. During his first days in office, he was not very confident and, as a result, constantly bombarded Dumbledore with letters for advice. During the last year of his tenure, Fudge was overcome by self-induced persecution delusions because Dumbledore claimed Voldemort had returned, and abused his own position to prevent that news from spreading, in order to protect both his position of power and the peace that the Ministry had worked so hard to maintain. In the end, when Fudge was forced to accept that Voldemort had indeed returned, the entire wizarding community called for his resignation and, after a fortnight of futile attempts to remain in office, in July 1996 he was replaced by Rufus Scrimgeour.
Scrimgeour's term ran for one year, in which he was little better than Fudge, despite his aura of experience and pro-activity; he created cover-ups and detained incorrect suspects to make it look as though he was accomplishing something. Making the same mistakes as his predecessor, he gave little chance to build up any effective defence as a whole, and it eventually cost him his life when he was overwhelmed and killed in August of 1997, with the official line saying that he had resigned. He was replaced by Voldemort's puppet, Pius Thicknesse.
Thicknesse, under Yaxley's Imperius Curse, was appointed as Minister, though he was really only Voldemort's puppet, with the Dark Lord effectively becoming the true Minister. While Thicknesse was to handle everyday business, which included changing the entire Ministry to suit the Death Eaters' ideology, Voldemort was free to extend his reign beyond the government. Voldemort did not announce himself Minister, but instead kept himself hidden in the shadows, in order to plant uncertainty and doubt within the wizarding community, preventing them from trusting anyone and forming any rebellion that may have overwhelmed the Ministry and the Death Eaters.
By the end of the war, Kingsley Shacklebolt was appointed as temporary Minister, the position later becoming permanent. His term led to the revolutionising of the entire Ministry, removing any and all corruption that had permeated it before and during the takeover.
One of the Minister for Magic's duties is to correspond with the British Prime Minister of Muggles of any ongoing events in the wizarding world that will or may affect the United Kingdom as a whole, e.g. Voldemort's return, or introduce themselves to the Muggle Prime Minister, should there be a change in office on either side.
A small portrait in the corner of the Prime Minister's office serves as an envoy between the two Ministers. It announces the arrival of the Minister for Magic, seeking the Prime Minister's reply (usually aquiescence to the unavoidable). It is believed that a Permanent Sticking Charm must have been placed on the portrait, for neither the Prime Minister nor his experts were able to remove it from its location.
Known correspondences
Sometime between 1990 and 1993, Fudge showed up to introduce himself to the newly elected Muggle Prime Minister. He also informed him of the existence of the magical population living among Muggles in secret, as well as assured him that he would not bother the Prime Minister unless it was something of great importance. He also claimed the previous Prime Minister tried to throw him out of the window, believing Fudge's presence to be a sabotage attempt.
In around July1993, Fudge showed up in the Prime Minister's office again, to inform him of Sirius Black's breakout from Azkaban, the wizard prison. He also told the story of Voldemort, in order to allow the Prime Minister to have an in depth understanding of what was going on, though as he dared not say the name out loud, he instead scribbled it on a piece of paper.
In August1994, Fudge turned up to report on the fiasco at the Quidditch World Cup, since its victims included Muggles. He also informed a bewildered Prime Minister that they would be importing dragons and a sphinx into Great Britain for the Triwizard Tournament, as part of the procedure (who possibly had no idea what Fudge was talking about).
Sometime prior to July 1996, a flustered Fudge appeared in the Prime Minister's office briefly to inform him that there had been a mass breakout from Azkaban, the wizard prison.
Around July1996, Fudge turned up and announced to the Prime Minister that the Second Wizarding War had begun, as well as that the Dark forces in their community were responsible for the various gloomy events occurring in the Muggle world. In addition, Fudge introduced his successor, Rufus Scrimgeour.
When Voldemorttook over the Ministry of Magic, it was possible that the the puppet Minister Pius Thicknesse was not sent to meet the Muggle Minister, as was the tradition in the past, due to the Death Eaters' attitudes towards Muggles and Muggle-borns. However, once Kingsley Shacklebolt was appointed Minister in 1998, it is possible, if not likely, that he did meet with the Prime Minister to not only introduce himself (indeed, he had been put in as secretary to the Prime Minister in 1996 to watch over his security)[3] but to assure the Muggle Minister that the war had ended.
Behind the scenes
In the American editions, the Minister is called the Minister of Magic.
In the films, both Minister of Magic and Minister for Magic seem to be acceptable, as different characters call it different names. For example, in Deathly Hallows: Part 1, when Scrimgeour arrives at The Burrow, George wonders what the Minister of Magic is doing there" likewise, when Kingsley's Patronus interrupts the wedding, he calls the Minister the same thing. However, when Pius Thicknesse gives his speech later in the film, he calls himself the Minister for Magic. The reason behind this is unknown.
Pius Thicknesse has the distinction of being the Minister for Magic with the shortest known term in office: 274 days (9 months and 1 day). The longest known term was that of Faris Spavin lasting 38 years. There has been a foreign Minister for Magic with a shorter term then Thicknesse's, though: Joshua Sankara, Minister for Magic of Burkina Faso for two days in 2006.
Since Kingsley's appointment as the next Minister for Magic is omitted from Harry Potter and the Deathly Hallows: Part 2, there is no mention of who is appointed to that position after the final battle.
Supposing that the liaison between the Minister for Magic and the Muggle Prime Minister has been the way we know since the Ministry's inception, as well as supposing that the Muggle Prime Ministers in the Harry Potter universe are all the same as their real-life counterparts, then the following table illustrates the Ministers for Magic that would have introduced themselves to the respective Prime Ministers:
