The Department of Magical International Cooperation is a major department within the British Ministry of Magic, serving as its foreign office and diplomatic branch. Its primary function is to manage relations with the magical governments of other countries, ensuring smooth collaboration and adherence to international wizarding law, most notably the International Statute of Secrecy. The department's responsibilities range from the highly significant, such as organizing large-scale events like the Triwizard Tournament, to the deeply bureaucratic, such as standardizing the thickness of cauldron bottoms for international trade. During the 1994-1995 school year, the department was headed by the famously diligent and multilingual Barty Crouch Sr.. His strict, by-the-book leadership style defined the department's reputation for being somewhat formal and stuffy, a stark contrast to the more flamboyant Department of Magical Games and Sports. After graduating from Hogwarts, Percy Weasley secured his first job within this department, where he was initially tasked with writing reports on mundane trade regulations, much to the amusement of his younger brothers. Despite the tedious nature of some of its work, the department plays a crucial role in maintaining the global wizarding community's stability and secrecy.
The Department of Magical International Cooperation is central to the plot of Harry Potter and the Goblet of Fire. Its primary responsibility in the narrative is the organization and execution of the revived Triwizard Tournament, a complex international event that required extensive coordination with the French and Bulgarian Ministries of Magic, as well as the heads of Beauxbatons Academy of Magic and the Durmstrang Institute. The department head, Barty Crouch Sr., acts as a key figure and one of the five champions' judges. His subsequent control under the Imperius Curse by Lord Voldemort and Barty Crouch Jr., his mysterious absences, and his eventual murder are pivotal plot points that demonstrate the infiltration of the Ministry of Magic by Dark Wizards. Percy Weasley's position within the department provides an inside look at its operations and serves as a major step in his personal journey of ambition, which eventually leads to his estrangement from his family. His pride in his work and his reverence for Mr. Crouch highlight the department's perceived importance within the Ministry hierarchy. The bureaucratic friction between this department and the Department of Magical Games and Sports, led by Ludo Bagman, over the management of events like the Quidditch World Cup and the Triwizard Tournament, further illustrates the inner workings of the wizarding government.
While the department's main office is where staff like Percy Weasley worked, it also oversees several important international bodies and sub-divisions.