As a child, the Inuk human rights lawyer Aaju Peter was sent far away from her native Greenland to live out her adolescence in Denmark, which has a long history of colonizing the island and which formally assumed its ongoing rule over it in 1814. Although Peter’s transfer to Denmark was viewed as a privilege for gifted children, she now sees it as a tragedy; it meant so profoundly losing touch with her culture that she had to re-learn her native language upon returning to Greenland as a young adult.

Peter’s childhood features centrally in the Danish director Lin Alluna’s documentary Twice Colonized, which tells the twinned stories of how Peter was colonized by the European nations that claimed ownership of her homeland, and how she has undertaken the work of decolonizing herself as a lawyer and advocate fighting for the autonomy of her culture. Alternatively poetic and political, intimate and historical, the film creates an emotionally rich, densely layered mosaic out of bits and pieces of Peter’s personal and professional life. Alluna has done excellent work in finding scenes and images that implicate numerous sides of her subject, while drawing in the web of relationships and power structures that surround her. Over the course of the film’s 90 minutes, these chunks add up to far more than the sum of their parts.

Lest that make Twice Colonized sound slow or pedantic, know that Peter’s screen presence is palpable, right from the very first moments where we see her contemplative, measured gaze staring down the beginning of another day. Whether she is advocating for the rights of Indigenous people at the European Union, finally ending a relationship with her abusive white boyfriend, or playing bingo at home while answering her granddaughter’s questions, she is a compelling and complex figure to journey with through this movie.

Filmed over seven years, Twice Colonized doesn’t follow a single narrative thread so much as move according to the themes and rhythms that emerge from Peter’s life. Hers is a story of loss in many forms, and although Peter is often seen bearing the pain of those losses, her resilience is clear in her endless energy for life and the way she tirelessly forges new connections. Early on, she is sitting on the floor of a classroom, talking with a group of students about the crises that confront her people. She declares: “It is no longer why [is this happening], it’s now how – how do we stop this,” before launching into the story of how her boyfriend non-consensually cut her hair in order to humiliate her. ”That just propelled me like a rocket in the other direction – I’m so proud of my haircut, it has totally focused me now on what I need to do.” The admiration on her audience’s faces is clear.

Among the connections Peter forges through the film is one with the documentarian Alluna, whose camera seems ever-present for all the details of her life. Filming Twice Colonized was a learning experience for both Alluna and Peter, even though the latter had previously been involved in other documentaries. Hands down, she said in a video interview together with Alluna, this one was by far the most personal, pushing boundaries with how much she was comfortable sharing on-screen. “It was really hard at times to have someone filming me,” she shared. “Mind you, I’ve been involved in three documentaries already, but this one was very personal and just right up my ass.” Indeed, Alluna captures her in such intimate acts as sleeping in bed, getting her teeth cleaned at the dentist, and playing dress-up with her granddaughters.

Ultimately, Peter came to respect the deeply personal nature of this film, even if it frightened her. “In this one I wanted everything shown,” Peter told me, “and how hard it has been for me to be colonized and to reclaim myself. I wanted Lin to show all the good all the bad and everything in between. I got really scared in the end, I said, ‘I can’t do it, I can’t release it.’ It was ridiculous, how could I want a documentary about my life?”

In order to properly tell this story, it was necessary for Alluna to let go of all the myths and misinformation she had been taught about the Indigenous occupants of Greenland. For Alluna, this meant a once-in-a-lifetime opportunity to deeply understand a culture that she had heretofore only known through the voices of other Danes like herself. Among other things, she had to very carefully hold the power dynamic that existed between her and her subject. “From that very first meeting with Aaju,” she said, “I learned so many things about myself and the history of my country. It was a real learning process for me.” Alluna chose to buck the convention of most documentaries, making it a priority to give Peter broad agency over the telling of her story, and also involving her in decisions regarding the shooting and editing of the film.

In this movie, scenes of Peter jumping on the bed and dancing to Tina Turner singing Proud Mary sit side by side with ones of her walking the streets of Copenhagen on duty as a lawyer, and then archival shots of her at the table of the Danish family that raised her during her adolescence. In a voiceover, Peter narrates how she and her brother were split up by the decision to send her to Denmark, and how the time there transformed her on the most basic of levels. “My whole world changed instantly,” she intones over images of her being brought into the Danish way of life. “I had to learn to sit at a table and use a knife and fork to eat my food.”

Peter now makes her home in Iqaluit, capital of Canada’s vast northern province Nunavut, which is primarily inhabited by the Inuit people, who autonomously govern themselves in a style similar to that of Greenland. She has found common cause between the people there and those in her native Greenland.

Midway through the film, she chooses to make the trip back to Greenland, to travel with her brother to see what’s left of her childhood home – standing there, the two of them try to process what has happened over the course of their lives. “Afraid of confronting what happened,” she says, “I haven’t been able to leave the trauma and learned behavior behind.” Later, the two siblings are sitting down in conversation, and he asks: “Maybe we could also talk about the bright side of the story?” Her reply is passionate: “No, the film crew already knows that it’s a tough trip. In this film we deal with the personal consequences that are a result of being governed by foreign countries.” Her brother looks almost frightened of the history she refuses to turn away from.

Perhaps through her work on Twice Colonized, Peter has seen that her past and the ongoing difficulties that it brings to her present life make her more human and more relatable. “A lot of people only want to show the good side,” she told me, “but what we all have in common is that we’re all experts in fuck-ups. We should be brave enough to show that. That’s what resonates with people, the courage to acknowledge that what people need right now isn’t a fake hero that’s perfect. For me a true hero is someone who goes through hardship and still fights for what they believe in.”

In a late scene, we see Peter working on a book about her life, and she poses this question beneath the title: “Is it possible to change the world and mend your own wounds at the same time?” This is the journey she is making, and the one that Alluna shows with great care and skill. It is both cultural history and personal narrative, and it is a story that needs to be told. “I’m glad we recorded this,” Peter said, “it’s for the Inuit, for my future generations.”

• Twice Colonized is available to rent digitally in the US on 12 July with a UK date to be announced