today, Angelina Jolie made her first official appearance in Siem Reap, Cambodia at the première of her new film First They Killed My Father, joined by her children Maddox, 15, Pax, 13, Zahara, 12, Shiloh, 10 and eight-year-old twins Knox and Vivienne. The mother-of-six, 41, whose eldest child Maddox was adopted in 2002 from an orphanage in Battambang, Cambodia, gave a free public screening of the memoir-based drama. Flanked by her proud children, the Hollywood star was the picture of elegance in a simple black dress with lace detailing on the shoulders. The harrowing film tells the story of the war time experiences of Angelina's friend and former refuge Cambodian Loung Un as a young child, and is set to be released on Netflix. Jolie, who directed the project, credited Maddox with convincing her to make the film after it languished for years. 'I wanted to focus not just on the war but on the love of family and on the beauty of the country and in fact I wanted to understand what my son's birth parents may have gone through. 'And I wanted to know him better and I wanted to know this country better,' she said. 'He was the one who just called it and said he was ready and that he wanted to work on it, which he did. He read the script, helped with notes, and was in the production meetings,' Jolie recently told The Guardian. Maddox was seen visiting the Angkor temple complex on Friday. 'It's the first time there's something on this size about this war in this country,' she said. 'I feel like nobody is here for themselves and everybody here to do any job is here to put something forward and help their country speak,' the American actress, who has been granted Cambodian citizenship, said. Cambodia's king and survivors of the communist regime will be among some 1,500 people invited to the debut screening of 'First They Killed My Father', directed by Jolie and based on the memoirs of Loung Ung. Loung Ung was five years old when Khmer Rouge troops, led by Pol Pot, swept into Phnom Penh plunging her family into a harrowing ordeal that saw them sent to brutal labour camps before her eventual escape to the United States. In its quest for an agrarian Marxist utopia, the regime killed up to two million Cambodians between 1975-79 through execution, starvation and overwork. Almost the entire film is in the Khmer language while the cast members and much of the crew were local hires, including the two child protagonists. The film is also co-produced by Rithy Panh, Cambodia's most acclaimed filmmaker. He lost almost all his immediate family during the Khmer Rouge years but went on to produce searing documentaries that helped break the silence surrounding the genocide. The première will be followed by screenings across Cambodia, some seven months before the film is released to a global audience on Netflix. Jolie's arrival in Cambodia marks a rare public appearance since her high-profile split last year from Brad Pitt in September. Together they had brought up Hollywood's most celebrated family with three of their six children adopted from overseas. Pitt, 53, and Angelina are currently locked in a custody battle over their children. Brad and Jolie - whose romance is believed to have begun during filming of Mr & Mrs Smith, while he was still married to Jennifer Aniston, in 2005 - are due back in court this month for a hearing in the ongoing case.