Clara Thalmann was one of ten children of a working-class family in Basel, Switzerland. Her father was German Socialist and internationalist who fled to Switzerland as a result of the Franco-Prussian War. In 1918 she joined the newly formed Communist Party of Switzerland after seeing the outcome of the October Revolution. Clara moved to France and worked for the French Communist newspaper L'Humanité in the 1920s, but broke with the newspaper following Stalin's rise to power in 1928. She returned to Basel where she met her future husband Paul Thalmann, who also had been born in Basel and had spent the past four years studying in Moscow, where he grew disillusioned and returned to Switzerland to work with dissident groups. As a result of their criticism of Stalin's policies, both were thrown out of the Party in 1929 and became involved with the Communist Party Opposition. In 1932 Clara Thalmann became editor of Arbeiter-Zeitung in Schaffhausen, working closely with Trotskyists and Left-Communists.
In Spain the newly elected Popular Front organized the People's Olympiad in Barcelona as a response to the 1936 Summer Olympics being hosted in Nazi Germany. She travelled south to attend as a representative of Arbeiterschwimmclubs (Worker's Swim Club) but due to the outbreak of the Spanish Civil War the games never occurred. Impressed by the strength and size of the working class anarchist movement in Catalonia and the successes of the Spanish Revolution, Clara joined the Durruti Column; a column of anarchists organized to fight against the Fascists. The militia marched from Barcelona to support the Republicans on the Aragon front, where Clara was joined by Paul Thalmann.
Conflict was developing within the Republican forces: the Stalinist Communist Party of Spain (PCE) attacked the Workers' Party of Marxist Unification (POUM). Under pressure from the Soviet Union, the PCE integrated the anarchist militias into the Republican army.
Tensions finally erupted following provocation from the Stalinists in an attempted takeover of the Barcelona Telephone Exchange and fighting broke out between the PCE and the Anarchists (CNT, FAI) resulting in the Barcelona May Days and resulting the members of the POUM and the UGT along with the Anarchists being defeated. In the end over 500 lay dead. Clara Thalmann and Paul fought with a group called "Amigos de Durruti" (Friends of Durruti).
At the barricades, Clara came to know George Orwell. During the repression that followed the events of May 1937, Paul and Clara Thalmann went underground. They were arrested a few months later when attempting to flee Spain by boat from Barcelona and were incarcerated by the Servicio de Información Militar (SIM), the Republican security forces. After several months in prison, they were released through the efforts of friends in Switzerland. After their release in 1937 they moved to Paris.
During World War II, Clara and Paul were active in the French Resistance and creation of the small revolutionary resistance group; Groupe Révolutionnaire Prolétarien. They secretly housed Jews or German-born revolutionaries and managed to not get caught. After the war, the two grew tired of living in Paris and in 1953 they settled near Nice and created a commune called "La Séréna". La Séréna became a haven for libertarian militants from various countries. They stayed in touch with new generations of student activists during the years 1960s-70s. In 1974 Paul and Clara published their memoirs entitled Revolution für die Freiheit Three years after Paul's death in 1981, Clara returned to Spain for the first time since 1937 to revisit the sites of the Spanish Civil War with comrade Augustin Souchy, publishing their experience in the documentary The Long Hope (Die lange Hoffnung).
Clara died on January 27, 1987 in her home in Nice from lung cancer.
- Studer, Brigitte & François Vallotton, Histoire sociale et mouvement ouvrier, 1848-1998/Sozialgeschichte und Arbeiterbewegung, 1848-1998, Editions d'En bas, 1997, ISBN 2-8290-0226-1 p.296
- Alba, Víctor & Stephen Schwartz, Spanish Marxism vs Soviet Communism: A History of the P.O.U.M, Transaction Publishers, 1988, ISBN 0-88738-198-7 p.124
- SolFed. "Clara Thalmann", Catalyst, #1 Winter 1987.