If people think of Trudie Styler and her association with Italy, they are most likely to conjure up an image of the wine-making estate she owns with her husband, Sting, in Tuscany. Few people would know her as a woman raised on a council estate in the English Midlands who wandered through the labyrinthine, mafia-ridden backstreets of Naples for her latest documentary, Posso Entrare? An Ode to Naples, which draws on the lives of a host of city residents. The documentary starts in the evocative Sanità district, where Styler meets Antonio Loffredo, a priest transforming the lives of young people who might otherwise have fallen prey to the Camorra mafia organisation, and where she visits multigenerational families living in case bassi – ground-floor homes that usually have just one room – and a door opening on to the street that provides the only source of air and light. She said her exploration of the city resonated with her upbringing “where as kids we were always in and out of each other’s houses, mums were gossiping, any neighbour had permission to yell at you or break up a fight and everybody was seemingly drinking tea all day long”. “There was a great community spirit,” she said in an interview with the Guardian before the documentary premiered at the Rome film festival on Monday night. “My mum helped to deliver children when the midwife was too busy – so we had that life and I think that gave me the confidence to wander around Sanità … you could peak in and see life going on, and I would tap on the shutter and ask: ‘Posso entrare?’ (can I enter?) and I would get a ‘certo’ (of course). The next minute the coffee was laid out, there was a child on my knee and we started talking. “I got to hear all the local stories that beget the politics of the place, what the needs and strengths are, and piece by piece, I built my cast of characters.” Styler had only visited Naples once before – in the 1990s for a concert by Sting. “I had no pre-impression of Naples,” she said. “But I did ask myself: W’hy haven’t I been?’ The city is safe and is getting safer. It is a thriving, buzzy place … I think Naples is having a Renaissance.” The people featured in the documentary include Nora Liello, a 90-year-old who swims in the Mediterranean for an hour a day “come hail or sunshine”. She recalls the day in 1938 when Adolf Hitler toured the city with Benito Mussolini before the dictators formed a military alliance during the second world war. At the end of the war, rebellious Neapolitans, including women and children, rose up against their Nazi occupiers, ridding the city of German troops without the help of the allies during what is known as le quattro giornate di Napoli (the four days of Naples). Liello also recalls watching the explosion of Mount Vesuvius in 1944, an event that claimed 1,200 lives. The documentary also features Roberto Saviano, the Neapolitan author famous for his book Gomorrah; Alessandra Clemente, a Naples councillor whose mother was killed in a mafia shootout; and the women involved in Forti Guerriere, an association fighting against domestic violence and femicide. “I focus really on the people who have remained [in Naples] because they want to make the city better, safer,” said Styler. “They have this ferocious, devoted loyalty and they are working as hard as they damn well can to make sure that people can be as safe and successful as they can.”