In “A South African Colouring Book” (1975), his mordantly ironic breakthrough work, Gavin Jantjes deployed Pop art and childhood learning to nail the brutish absurdities of the apartheid regime in which he grew up. One of its 11 screenprints, “Colour This Whites Only”, bearing a stencilled watercolour tray, has a torn-out wartime quotation from then prime minister John Vorster, allying his Christian nationalism with Hitler’s National Socialism. Photographs of the aftermath of the 1960 Sharpeville massacre of black protesters are collaged in “Colour These People Dead”.

The work won plaudits in London in 1976, when Jantjes was the first African artist to show at the Institute of Contemporary Arts, just as schoolchildren demonstrating against mandatory Afrikaans (the language associated with apartheid oppression) were mown down in the Soweto uprising. The image of 12-year-old Hector Pieterson’s bloodied corpse in a protester’s arms was deconstructed in Jantjes’ anti-apartheid posters, and in screen-prints such as “City Late” (1976) he collaged news cuttings with shots by the photojournalists George Hallett and Peter Magubane.

These works are on show in Gavin Jantjes: To Be Free! A Retrospective (1970-2023), at the Sharjah Art Foundation in the United Arab Emirates, the first retrospective of the 75-year-old, Oxfordshire-based artist and curator. (It moves to the Whitechapel Gallery in London in June 2024.) Across three galleries, the show extends to Jantjes’ recent non-figurative paintings, reaffirming the viewer’s imaginative agency and his own artistic freedom.

“A South African Colouring Book” was banned in 1978, while Jantjes was a refugee in Europe. He returned only in 1994 after more than 20 years in exile. In another of its screen-prints, “Classify This Coloured”, are the artist’s ID pass, a text on race laws and a photo inset of him in a defiant afro. Born in 1948, as apartheid was, Jantjes grew up in District Six, a multi-ethnic Cape Town neighbourhood declared white under the Group Areas Act in 1966, and bulldozed. Though his family house on Anglican church land was saved, a highway was built next to it. With community support, Jantjes became the sole black student at the University of Cape Town’s Michaelis School of Fine Art. District Six, he tells me in Sharjah, was a “wonderful, creative hub” with theatres, carnival bands and an opera company. “There were other religions — Muslim, Jewish. The cultural mix I grew up with shaped me. When I came to Europe, I knew it could exist.”

Studying in the early 1970s at the University of Fine Arts of Hamburg, Jantjes worked with master printmakers. Moving to Wiltshire in southern England, he learnt from Richard Hamilton’s “Swingeing London 67” (1968) that “you could break the rules”, adapting Pop art for political ends, while embracing the “postmodern shift to multiples” to share hard-won information in a pre-digital age. Today, the early screen-prints’ innovative design elements, such as photos tiled to resemble contact sheets, stand out, but their artistry was often overlooked.

In the same room is a digital recreation of a lost mural, “The Dream, The Rumour and The Poet’s Song” (1985), from Brixton in south London. In a nod to Picasso’s “Guernica”, the 7.5 metre long mural, created with Tam Joseph and destroyed in the mid-1990s, variously spotlights a police boot on a face and the poet Linton Kwesi Johnson.

The early figurative paintings are complex and compelling compositions, some set against Table Mountain, with flattened forms and pastels reminiscent of poster art. In “Quietly at Tea” (1978), politicians and clerics conspire, as a bow-tied waiter appears poised between servility and revolt. In a nod to Soweto in another painting, a shadowy man in dark glasses observes figures blasted by bullets in a cone of light, as he slips off through a doorway.

The Korabra series (c1984-90) abandoned narrative. Living near the former slaving port of Bristol, Jantjes was appalled by the absence of “even a plaque”. In “Untitled No 3” (1985), one of seven large-scale paintings, a male and female figure on an auction block, their heads grotesquely bowed, are shadowed by their proudly upright selves. In “Untitled No 2” (1986), a vast blue ocean is traversed by white coffins with sails. Jantjes mixed “sand from budgerigar cages” into his own paint, along with commodities such as cotton, wool and sugar, in a harbinger of contemporary British art exploring transatlantic slavery.

The Zulu series (c1984-90) ventures further into poetic ambiguity. “Vaal” (1987), an acrylic painting of an ancient stone circle and ox wagons under a lowering grey sky, rebuffs myths from the Boers, European-descended settlers, of voortrekkers (“pioneers” in Afrikaans) settling in an empty landscape. Thrilling, midnight-blue “sky charts” in Indian ink on khadi cotton-paper counter with African cosmogony. In the acrylic-on-canvas “Untitled” (1988), three figures with elongated heads, recalling both Khoisan rock art and extraterrestrials, allude to a Khoisan creation myth of a girl creating the Milky Way with burning embers. For Jantjes, the sky is a “vast space for the imagination. It belongs to everybody — and it’s important for Africa.”

This series validates classical African art not simply as raw material for a European avant-garde. A reddish diptych, “Untitled” (1988), depicts an armless clay doll and an African mask, while a sculptural cone, cube and sphere beside the paintings reference Cubist forms. This work, acquired by MoMA in New York, is “not a rupture or refusal” of Modernism, says Jantjes. “It builds a bridge.” In a key painting, “Untitled” (1989), a white umbilical cord links a Fang mask from Gabon with a figure from Picasso’s “Les Demoiselles d’Avignon” (1907), binding the two across a night sky, in a dialogue of equals.

In 2014, Jantjes returned to the studio after 20 years, most spent in Norway as a curator, later settling in Witney, Oxfordshire. Though he had always felt he needed a subject, he was aghast that, as a curator, “I was reading, not looking”. The Exogenic Series (Aqua) (2017) evokes the luminous fluidity of water with almost transparent washes. A Sharjah residency enabled his largest paintings to date, whose depth of colour draws the viewer into mysterious, almost undersea, worlds. Rather than “abstract”, which “means you already have a subject”, Jantjes terms this art “non-figurative: you start with a blank canvas and don’t know what will happen”. His goals are self-reflection and communal awe, comparable to visiting the Victoria Falls: “It makes you aware of yourself — and the person next to you is having the same experience.”

His new series, Kirstenbosch (which he hopes will be ready for the Whitechapel show) is named after Cape Town’s botanical garden. Its delicate paintings and pastel drawings, he says, “begin to look like flowers”. Brecht wrote that to speak of trees is almost a crime, a silence about injustice. Yet, as Jantjes’ life and work attest, any critique of this world must surely leave space to imagine others.

Al Mureijah Art Spaces, Sharjah Art Foundation, UAE, until March 10, sharjahart.org. Whitechapel Gallery, London, June 12-September 1, whitechapelgallery.org