The execution of Ethel and Julius Rosenberg at sundown on 19 June 1953 was one of the darkest moments in recent US history. The married couple were the only American civilians to be put to death for espionage-related activity during the Cold War, after they were convicted of passing top secret information to the Soviets. Their deaths left their two young sons orphaned.

It was claimed that the atomic weapon designs shared by Julius Rosenberg enabled the Soviets to acquire nuclear capabilities earlier than expected. The USSR staged its first nuclear test, RDS-1 (rechristened Joe-1 by the Americans), in August 1949. KGB files declassified after the country’s dissolution confirmed Julius’s involvement in the plot. But the death sentence for Ethel – who was found guilty of typing up notes that Julius passed to his handlers – remains a controversial decision.

For over two years, the pair had been languishing in jail. During this time, the case became a cause célèbre. Particularly in France, there was widespread sympathy for the Rosenbergs, with recognition that the alleged espionage would have taken place when the Soviet Union was an ally in the fight against Nazi Germany. In the aftermath of the US bombings of Hiroshima and Nagasaki at the end of the Second World War, there were also many who felt that the development of Soviet atomic weapons was a necessary evil to deter the United States from launching further nuclear attacks.

Artists too rallied in defence of the couple. Among them was the renowned French Cubist, Fernand Léger – a member of the Communist Party – who designed a bold double portrait of the couple in his distinctive colourful style. The couple’s faces are shown overlapping, Ethel in frontal view and Julius in profile, alongside a peace dove – at the time also a common symbol of Communism. Two hands are shown with fingers entwined, a bracelet on one possibly a reference to a press photograph of the couple embracing in handcuffs during their trial. The images are framed by the words ‘Liberté, Paix, Solidarité’ (‘Liberty, Peace, Solidarity’).

Léger printed his design on silk scarves which he intended to sell to raise money for the Rosenberg’s defence. The couple were executed before he could put the plan into action – but one of the scarves now takes pride of place in the home of Robert Meeropol, the couple’s youngest son who was 6 years old when his parents died (his brother Michael was 10). Léger added the handwritten dedication to this scarf: ‘à Robert, orphelin’ (‘To Robert, orphan’).

Another double portrait print was designed by fellow Communist artist, Pablo Picasso. As with Léger’s scarves, it was intended to be sold to raise defence funds and Picasso would give a dedicated copy to the two boys. In the annual Salon d’Automne, which opened at Paris’s Grand Palais in November 1953, the strength of feeling against the Rosenberg’s execution was made clear. Numerous French artists joined Picasso and Léger in exhibiting artworks in tribute to the Rosenbergs and denouncing what they felt to be a grave miscarriage of justice. A press photo shows Jean Venitien’s large oil painted canvas Honour to the Rosenbergs, an unusual style for the impressionist artist who was better known for his paintings of Southern French landscapes.

The Salon also included André Fougeron’s monumental Socialist Realist painting Civilisation atlantique (Atlantic Civilisation), now held in London’s Tate Modern. A scathing critique of America’s influence in Europe, the caricature-style narrative shows widespread suffering caused by corruption, colonisation, consumerism and militarism. In his condemnation of French foreign policy in North Africa, Fougeron introduced visual tropes that he would build upon five years later in his canvas Massacre à Sakiet III (Massacre at Sakiet III), explored in an earlier Espionart post. Central to this modern history painting is the towering image of the electric chair, used to execute Ethel and Julius Rosenberg at the notorious Sing Sing Correctional Facility in New York.

Over in the United States, artists such as Hugo Gellert and Arnold Mesches also expressed their support for the Rosenbergs as prisoners of conscience, who had paid the ultimate price for their beliefs.

The Rosenberg orphans, Robert and Michael, would later be adopted by songwriter Abel Meeropol, whose commitment to fighting injustice was shown in his famous anti-lynching song Strange Fruit, recorded by such greats as Billie Holiday and Nina Simone. The family continue to campaign to this day for justice for their parents and exoneration for Ethel, and to support the children of other activists in the United States, through the Rosenberg Fund for Children.