Early in Jon Snow: A Witness to History, a too-brief documentary mostly about the reporter and news anchor’s professional life, Snow admits that he wasn’t sure if journalism was the career for him. In 1975, he was cutting his teeth as a cub reporter for LBC Radio when he heard rumblings of an incident on Balcombe Street in London. Thanks to his famous love of cycling, he was first on the scene, breathlessly reporting the IRA siege that was unfolding, live, as it happened. “I should have been afraid, yet I was so busy reporting I didn’t get the chance,” he says. It made him certain that journalism was indeed the career for him, and this fascinating documentary follows him through his early years as a foreign correspondent for ITN and then his 32-year stint as the anchor for Channel 4 News, a seat he only recently vacated. As he covered most of the major events of the last five decades or so, it also serves as a potted history of the late 20th and early 21st century, from the death of Diana, Princess of Wales to 9/11, then the rise of Trump and his “fake news” cacophony. If it is a potted history, it is, at times, a difficult one to witness, even as a distant spectator. Snow does attempt to examine, albeit fleetingly, the psychology of those who report on war and are drawn to the danger and excitement of conflict on the ground. During his years as a war reporter, Snow witnessed much brutality and horror; in many of his reports, there are dead bodies strewn on the ground, falling out of cars, or piled on to the back of trucks. As a young man, he lived and worked as a teacher in Uganda for a year, which later endeared him to Idi Amin. “We really got on rather unpleasantly well,” he recalls of one of their meetings, before moving on to a jaw-dropping anecdote about a dilemma he faced when the dictator fell asleep in his presence. As much as this is a history of the recent past, it is a portrait of the man himself. We meet his wife and young son, and learn about his own early life as the child of a “remote” bishop. “My father always thought I was the least bright of his three sons,” says Snow, with more breeziness than you might expect. There is a photograph of Snow as a boy, shaking hands with the Queen. He tells a sweet anecdote about meeting Harold Macmillan, too, which bestows his “witness to history” credentials on him from childhood, though he tends to speak of his life as if it’s all been a series of events that somehow unfolded of their own volition, astonishing even him. Clearly that’s not the case, but it is particularly moving when he talks about Nelson Mandela. Snow was expelled from the University of Liverpool when he was 22, for his role at a sit-in protest against apartheid in South Africa. By 1990, he would find himself in South Africa, reporting on Mandela’s release from prison. “I can’t make it add up, even now,” he says, warmly. Four years later, Mandela would become president, and Snow got the chance to interview him. It sounds as if it remains the highlight of his very long career. When Snow took his seat as the anchor of Channel 4 News – a role that suited him, suggests Ray Queally, a cameraman who worked with him during the Iran-Iraq war in the 1980s, because he was “part journalist, part showman” – he shifted focus, though he did occasionally return to on-the-ground reporting in Gaza and at the site of the Grenfell Tower disaster. And he was there in the studio for the major events that have shaped our recent world, from the “war on terror” to the election of Obama, right through to the rise of Trump. By the end, the documentary has become a discussion about the notion of impartiality, and whether the accusation that Snow is “an old lefty”, as he puts it, has any impact on his reporting. He says not, and cautions against a world in which the media are attacked by those in power, and in which the idea of truth becomes relative. At the outset of this film, Snow explains that after 50 years of chasing stories, he wants to discover what he has learned from all that he has seen. There is little chance of anyone finding that out over the course of an hour, and A Witness to History can barely skim the surface. Snow’s books go much deeper. But for a man who has spent most of his life on screen, a televised memoir is more than fitting.