The late 1960s marked a creative turning point for Frank Stella. The controlled minimalism of his early works (evident in his brooding, rectilinear Black Paintings) gave way to bold, rainbow palettes and sculpted surfaces. He also experimented with canvas shape and began to incorporate curvilinear elements into his compositions.

His celebrated Protractor series (1967-71), of which Hiraqla Variation II forms part, features multi-coloured arcs arranged to resemble the full and half circles of a protractor. The curved forms are inspired by the rounded, vibrant patterns traditionally found in Islamic art, while the titles draw on the names of ancient circular cities in Asia Minor.

Most widely known for his children’s illustrations, there is a disarming quality to Oliver Jeffers’ art. His graphic worlds filled with colour and imagination have adorned picture books worldwide. The result, when confronted with his paintings of political and socio-geographical narratives, is to really sit up and take notice.

There Are None So Blind (2018) reflects Jeffers’ concerns about the changing natural environment. Combining beauty and disaster – a starry sunset against the rising of the ocean – the scene pokes fun at our human propensity towards disaster. It’s through the subtle approach of his critique that the artist hopes to turn the tide.

Agnes Martin suffered from debilitating psychosis: she had visions and heard voices and was hospitalised repeatedly. In 1967 she fled New York, resurfacing around 18 months later on a remote mesa in New Mexico.

But these turbulent personal experiences did not directly shape her quiet, structured compositions. Rather she strived to capture the intangible essence of being — beauty, happiness, innocence, joy.

Painted just one year before her death, Untitled #1 2003 features two opaque triangles that evoke mountainous forms. ‘Nature is like parting a curtain, you go into it,’ she said. ‘I want to draw that quality of response from people, an experience of simple joy.’

Andy Warhol and Marilyn Monroe: the King and Queen of Pop. London Original Print Fair takes place this week (1-8 May), a medium much popularised by Warhol and of which ‘Marilyn Monroe’ is one of the most iconic. It was the first of the artist’s signature screen prints, and went on to become one of the most significant and recognisable works of art of the 20th century. The portrait reflects Warhol’s (and society’s) obsession with celebrity culture, with the diptych style inspired by the Byzantine icons of Christian saints - a comment on the modern-day worship of stars like Monroe. Graphic, repetitious and strikingly visual, it’s an example of how Warhol’s work anticipated social media iconography decades before Instagram was ever invented. Sixty years later, this one’s still going viral.

In March 1945 allied bombing destroyed the Vienna State Opera. ‘The flames sucked air from the staircases and halls,’ recalls the model, muse and photographer Lee Miller. ‘The auditorium and stage are gutted.’

This striking photograph shows the opera singer Irmgard Seefried singing an aria from Puccini’s Madame Butterfly amidst the ruins. Taken in 1945, it forms part of Miller’s captivating coverage of the Second World War. As an official US war correspondent, Miller documented everything from life at the front and German concentration camps, to women's wartime experiences and the liberation of Europe. Traumatised by the horrors of conflict, however, Miller gradually disappeared from public view.

Louise Bourgeois (1911–2010) is often referred to as the reluctant hero of feminist art. Best known for her giant spider sculptures, the artist explored patriarchy, motherhood and what it meant for women to be subjects rather than objects of art.  Bourgeois’s gigantic series of spider sculptures are arguably her most iconic works, which are nightmarish and sublime in equal measure. Bourgeois once explained that she chose the spider as a subject because its traits reminded her of her mother.

“She was deliberate, clever, patient, soothing, reasonable, dainty, subtle, indispensable, neat, and as useful as a spider”. Having been the subject of many public exhibitions around the world from London’s TATE Modern, Rockefeller Centre, New York and Bilbao, Spain, Bourgeois’s spiders have become some of the most widely recognizable sculptures in the world.

Contemplating the expanse, the magic and the beauty of nature, Anish Kapoor’s ‘Sky Mirror’ brings the sky down to the earth. A dazzling feat of light and reflection – signature elements of Kapoor’s style – the work was the centrepiece of the artist’s Houghton Hall exhibition in 2020.

Unveiled in 2001, Sky Mirror was commissioned by the Nottingham Playhouse, and versions of the sculpture now exist all over the world, including at the Hermitage Museum in St Petersburg, Russia. A celebration of the ever-changing environment, it implores us to look up and around – a reminder that nature is the greatest work of art.

Evocative and mysterious, Kevin Francis Gray’s sculptures transcend the art of mere likeness. Working at the intersection between the abstract and the figurative, the Irish artist experiments at the level of form and texture to imbue his portraits with a psychological depth – bringing life and character to such subjects as Hades.

Francis Gray’s rendering of his King of the Underworld is intimidating and humorous in equal measure. Working first in clay before translating into marble, you can see the mark of the sculptor’s hands and tools, bringing a fluidity to his work – here in fittingly grand display at the Villa Santo Sospir in France.

Activist art. In the wake of urgent conversations around racial injustice and inequality, the powerful symbolism of Hank Willis Thomas’ sculptures has gained the artist an international platform and momentum. Each one an ode to the importance of unity – as is the title of this 22-foot sculpture, installed in Brooklyn, New York in 2019 – his works are a hopeful, levelling reminder for us to come together and embrace our common humanity.

‘The large-scale sculpture of a bronze arm pointing toward the sky is intended to convey to a wide audience a myriad of ideas about individual and collective identity, ambition, and perseverance,’ says Thomas – whose vision looks set to continue lighting the world’s way.