One Saturday afternoon in 1972, Linton Kwesi Johnson was walking through Brixton market when he noticed three plainclothes police officers arresting a young man. Seeing their excessive use of force, his training kicked in. He had been in the youth section of the British Black Panthers and knew to write down the name and address of someone in a situation like this, because “the police would often arrest black youths and lock them up in remand centres without informing their next of kin”. But in retaliation the officers arrested Johnson too, throwing him into the back of a police van where they beat him up and racially abused him. It would take more than six months before he was acquitted of the charges of assault levelled against him. This anecdote, buried in this new collection of Johnson’s prose, braids together the themes of the book and even his life: a practised solidarity with his fellow man, the workings of a racist state, and the vitality of the black radical tradition. It also reminds us of the brutal contingencies of a life like his. LKJ, as he is known, is now recognised as one of the great living poets of the counterculture. Penguin has anthologised his verse. He has honorary degrees and awards to his name. But he was once a young militant trying to survive a hostile environment. Born in 1952 in rural Jamaica, he grew up a “barefoot peasant boy”. Neither of his parents was fully literate. He arrived 11 years later in an unforgiving London – a city of racists and menacing agents of the state. So joining the Panthers was about survival, but it also served him in other ways: it was through their library that he discovered gems of black literature like WEB Du Bois’s The Souls of Black Folk. Together with the influence of reggae, particularly the improvisatory patter of Jamaican DJs, these moved him to write poetry. Johnson is best known for his verse from the 70s and 80s, which gave form to the lifeworlds of Britain’s black migrants and their children, the uprisings and depressions, using a distinctly Jamaican idiom. He was like a one-man Greek chorus to his generation’s political struggles, providing an unsparing and sensuous account of British-Caribbean life. His language had an inherent musicality and would be set to music on LPs like Forces of Victory and Bass Culture. In 1980, he appeared on the Old Grey Whistle Test, reciting – in his commanding, melodic drawl – perhaps his most well-known poem: “Inglan is a bitch / dere’s no escapin it.” Time Come tells us what else he was doing, through reviews, interviews, essays, features, speeches, lectures, blog posts and obituaries. It is mainly journalistic copy, sometimes shorn of his poetic voice, often too short, but with an attentive and empathic eye on its subjects, whether those are Dennis Bovell, his musical collaborator whom he profiled for Race Today, or the transformative events of 1981 – the New Cross fire, the Black People’s Day of Action and the riots across England. The impression is of an uncompromising intellectual for whom there was no separation between politics and art. “In the beginning,” Johnson wrote in a 2010 essay, “writing verse was for me a political act and poetry a cultural weapon in the black liberation struggle.” The struggle came with a soundtrack. Johnson’s skills as a cultural critic are revealed by a crackling essay called Jamaican Rebel Music, published in 1976, the year he graduated from Goldsmiths college with a degree in sociology. “The popular music of Jamaica today is a music whose pulse is ‘the groundbeat of survival itself’,” he wrote. “[It] embodies the historical experience of the Jamaican masses.” Johnson made sense of reggae’s political and spiritual ethos: it was steeped in the dynamics of suffering and rebellion, he argued, which characterised the island’s experience of slavery, colonialism and neo-colonialism. He also anatomised a new cultural figure: the “dub lyricist”, the soundsystem DJ turned poet. Big Youth, I Roy and Dillinger were his lodestars. In fact, the writing is thick with references to peers, inspirations, comrades and enablers – Johnson is always keen to deflate the myth of individual greatness. They include the collective at Race Today magazine, where he worked as an editor; mentors such as the writer Andrew Salkey and activist John La Rose (“the most remarkable human being I have ever known”); and Caribbean poets including Louise Bennett, Kamau Brathwaite and Mikey Smith. Time Come functions as a self-portrait, but it also offers – as Paul Gilroy notes in his introduction to this “scandalously overdue” book – a window on to a bustling, transnational landscape of thinkers and doers. Decades later, Johnson sits more comfortably in the space he carved out for himself in Britain. There may even be something of a LKJ renaissance going on. Mid-lockdown, viewers of Steve McQueen’s Small Axe will have heard him recite his seminal poem New Crass Massakah during an elegiac sequence of documentary montage. In a very different register, viewers of The Crown will have seen an episode in season four that styles the Queen as a kind of anti-apartheid activist, and heard in the background of one scene Johnson’s anti-fascist anthem, Fite Dem Back. And then, most surprisingly, over the end credits, a song whose vengeful melancholy hasn’t aged a day: Inglan Is a Bitch. Time Come: Selected Prose by Linton Kwesi Johnson is published by Picador (£20). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply.