The character is introduced in Harry Potter and the Chamber of Secrets; he is responsible for sending Hagrid to Azkaban when the Chamber of Secrets is reopened. In Harry Potter and the Prisoner of Azkaban he makes a number of appearances; first, he greets Harry at the Leaky Cauldron. Later he inadvertently provides valuable information to Harry; that Sirius Black was James Potter's best friend.
At the end of Harry Potter and the Goblet of Fire Fudge refused to accept that Lord Voldemort had returned and in Harry Potter and the Order of the Phoenix Fudge orchestrated a smear campaign to discredit Dumbledore and Harry Potter. At the end of the book Fudge was forced to accept that Voldemort had returned.