The topic was actually offered to her, Margarethe von Trotta said to DW in an interview, listing the reasons: Firstly, she always told everybody, everywhere that legendary Swedish film director Ingmar Bergman had been her "master." And secondly, von Trotta recalled, it was Bergman who inspired her to become a film director herself.

German director Margarethe von Trotta's new work Searching for Ingmar Bergman premiered on May 15 at the 71st Cannes Film Festival in the section "Cannes Classics," which presents restored masterworks of film history, as well as documentaries on significant directors and film artists.

Read more: Legendary German director Margarethe von Trotta lightens up with New York comedy

Trotta's film to run worldwide

Ingmar Bergman was born 100 years ago on July 14. Events commemorating his centennial birthday are expected to take place over the next months, and von Trotta's work will likely to play an important role.

Searching for Ingmar Bergman contains clips from various films made by the Swedish director, as well as interviews with his artistic companions and family members. The German director traveled a lot for her project, visiting the original locations of Bergman films and exploring the cinematic universe of one of the most significant directors of the 20th century.

Von Trotta also met famous Bergman collaborators, such as actress Liv Ullmann and screenwriter Jean-Claude Carriere. She interviewed Bergman experts, as well as directors of various generations in order to find out how the Swedish filmmaker has continued to influence filmmakers through today. 

A friendship with Scottish roots

But why did von Trotta choose to produce a documentary for what would have been Bergman's 100th birthday? She had already met Bergman in 1977 in Munich. Due to accusations of tax evasion, the Swede had left his home country for Germany, where he directed films and also worked in theater.

It was only 13 years later that the contact between them grew closer. In 1990 Trotta and Bergman were both jury members of at the European Film Awards. As the jury's first president, Bergman had the right to appoint the jury's members: "That fall, we sat together, all by ourselves, in a remote golf hotel in Scotland." Von Trotta remembers that the location was chosen by Bergman because "he was afraid of too many people around him." Actress Deborah Kerr, screenwriter Suso Cecchi D'Amico, Greek director Theo Angelopoulos and French actress Jeanne Moreau were also there.

Von Trotta recalls: "One evening, he [Bergman] told me that he admired my film The German Sisters (Die bleierne Zeit; also known in English as Marianne and Julianne) and that I had given him courage." Her film was released in 1981, at a time when Bergman had been "very depressed," von Trotta recalls.

Bergman explained to her that her film about the lives of two sisters in Germany's far-left, militant Red Army Faction (RAF) terrorist group had encouraged him to go on with his work. "He complimented me a lot," von Trotta recounted. "And of course, I was very happy about that." She subsequently admitted to him: "It was only because of you that I became a film director in the first place."

Praise from an idol

Their conversation in Scotland was "a highly important moment in my life," von Trotta told DW. "It makes perfect sense, when you have an idol, a master. If he then tells you that what you do is great, it's the best compliment you could possibly get." Von Trotta also remembers that a common friend, director and author Jörn Donner, later told her: "Yeah, but you shouldn't take it so seriously. He's a womanizer, who only wants you to feel comfortable around him."

However, it looks like Bergman really meant what he said. Two years later, the Swedish director was asked by the Göteborg Film Festival to produce a list of films that had influenced and impressed him. Bergman put 11 names on his list, including films from Japanese director Akira Kurosawa, Italian Federico Fellini, Englishman Charlie Chaplin and Dane Carl Theodor Dreyer. And then came a woman's name: Margarethe von Trotta and her work The German Sisters.

"The film world's most famous names were on the list," von Trotta proudly remembers. "And there I was, at the very end, for my film The German Sisters. I was the only woman, the only German, and the youngest of all the names on the list."

Bergman honored in Cannes

All the famous filmmakers on the list have since died, Bergman said in her DW interview: "I'm the only one on the list who's left."  She mused that could well have been one of the reasons of why The Ingmar Bergman Foundation asked her to produce a film on the Swedish director.

At first, the task intimidated her, she said. After all, she couldn't be sure whether or not she would be able to produce a film that would do justice to her idol. Besides, she had never directed a documentary before: "That can turn into a total disaster, and yet, I just couldn't say no."

Margarethe von Trotta's documentary "Searching for Ingmar Bergman" will celebrate its world premiere in Cannes on May 15, 2018. The Cannes Film Festival has a special relationship to the Swedish star director: In 1997, Bergman received the honorary "Palm of Palms" award, the festival's highest prize which was awarded just that one time to the Swedish director for his entire body of work. Von Trotta's documentary can't be that far off the mark.

Read more: 10 memorable winners of the Palme d'Or

Margarethe von Trotta has directed her documentary "Searching for Ingmar Bergman" together with her son, director Felix Moeller. The film will hit German movie theaters on July 12th, two days ahead of the Swedish director's 100th birthday.