, 1864: The 18-year-old, idealistic Ludwig gets crowned as the King of Bavaria. His first official act is a lavish support for the inspired but indebted composer Richard Wagner, who settles in Munich after Ludwig's request. Ludwig's cabinet cannot understand his support for the arts and is furious about Wagner's expensive lifestyle. Ludwig tries to find a faithful friend in Wagner, whose music he loves, but these hopes get shattered: behind the King's back, Wagner has an affair with Cosima von Bülow, the wife of Wagner's opportunistic conductor Hans von Bülow. In order to avoid a scandal, Wagner has to leave Munich. Ludwig continues to support Wagner and his projects, but he still feels mistrust against him. Another important person for Ludwig is Empress Elisabeth of Austria, his independent and charismatic cousin. During a meeting with other aristocratic families in Bad Ischl, Elisabeth and Ludwig get close to each other and they share a kiss. However, Elisabeth is more interested in bringing up a marriage between her beautiful, cultivated sister Sophie and Ludwig, but the king ignores Sophie. Disappointed by Wagner and Elisabeth, Ludwig starts to withdraw from public into dream worlds. Ludwig wants Bavaria to stay in neutral position in the Austro-Prussian War 1866, but his cabinet has another opinion and they eventually support the Austrian's loser's side. Ludwig ignores the war and stays in his castle, much to the irritation of his younger brotherOtto and his close confidant Count Dürckheim. Dürckheim advises him to a marriage in order to prevent loneliness. Shortly after Ludwig becomes aware of his homosexuality, he suddenly announces his engagement with Sophie in January 1867. His mother and the cabinet send an actress into his apartments, who is instructed to give him sexual experience. Ludwig feels angry about the actress and throws her into his bathtub. Ludwig has doubts if he can be a good husband to Sophie who loves him, and he postpones and eventually cancels the marriage. Instead, he starts having relationships with his servants, although the devout Catholic feels guilt about his homosexuality. Bavaria supports the Prussian army in the Franco-Prussian War 1871, but during the following Unification of Germany the Bavarian King loses a lot of his sovereignty to the Prussian emperor Wilhelm I and Chancellor Otto von Bismarck. Shortly after the Franco-Prussian War, the mental health of Ludwig's younger brother Otto declines and doctors have to take care of him. Ludwig is shocked by his brother's illness. Ludwig does not care about politics anymore, instead, he spends his money building Neuschwanstein Castle, Linderhof Palace and Herrenchiemsee. The cabinet feels increasingly frustrated by the eccentric and secluded king's debts. In 1881, the king has a short but fierce friendship with actor Josef Kainz, whose Romeo performance he adores, but Kainz is mostly interested in the king's money. Ludwig also hosts some orgies with his servants. When his cousin Elisabeth wants to visit him after a long time, he refuses to see her. In 1886, the psychiatrist Bernhard von Gudden declares that Ludwig is mentally insane, following the advice of his scheming Cabinet. With the help of his faithful servants, Ludwig can arrest his cabinet for a few hours. His friends advise him to fight against the accusation that he is mentally insane, but he only feels world-weary and depressed. Eventually, his uncle Luitpold is declared Prince Regent of Bavaria. Ludwig is brought to Berg Castle near Lake Starnberg, where he has to stay under arrest and gets psychological treatment. Two days later, Ludwig and Bernhard von Gudden leave the castle for a walk. A few hours later, their corpses are found in the Lake Starnberg. The film leaves the mysterious death of Ludwig open.
The Director's cut by Visconti was over four hours long, which the film's distributors deemed as too long. Ludwig was then shortened to three hours at the premiere in Bonn on 18 January 1973. The cutback was without Visconti's consent, but the director was not able to stop it, also because he was in bad health after a stroke during filming. The depiction of Ludwig's homosexuality caused a controversy, particularly in Bavaria, where Ludwig was admired by many Conservatives. Among the critics was Bavarian prime minister Franz Josef Strauss, who was also in the film's premiere. The distributors feared controversy and a further 55 minutes were cut from the premiere version, reducing the film to two hours. Scenes with homosexual hints and some of the more philosophical dialogues in the film were cut in order to make the film more popular with mainstream audiences. There are at least four different versions of the film, which according to the All Movie Guide "suffers greatly when shortened, as every moment is essential to the story." German film critic Wolfram Schütte wrote that those who saw the shortened version "haven't seen the film". The film was restored to its four-hour length by Ludwig-film editor Ruggero Mastroianni and Ludwig-screenwriter Suso Cecchi d'Amico in 1980, four years after Visconti's death. This version had its premiere in 1980 at the Venice Film Festival.
