One of the most famous activists of the German and international socialist and women's movement, Clara Zetkin entered the history of the 20th century not only as an active communist, but also as a woman reformer who played an important role in the development of the European movement for women's rights. In Soviet times, the main merit of Zetkin was the establishment, at her suggestion, of International Women's Day.

Clara Zetkin, nee Eisner, was born in 1857 in the small Saxon town of Wiederau in the family of a rural teacher. Already at a young age, Clara stood out among her peers with her curiosity and tenacious memory: at the age of 9, the girl read all of Goethe and Schiller and recited their poems with pleasure, and at 12 she quoted excerpts from the History of the French Revolution by historian Thomas Carlyle.

While still a student at the Leipzig Pedagogical Gymnasium, a prestigious educational institution, she began to attend secret meetings of the Social Democrats, and in 1878 joined the Socialist Workers' Party, later renamed the Social Democratic Party of Germany (SPD). At the same time, she met her future life partner, the Russian revolutionary emigrant Osip Zetkin, with whom she was soon forced to leave for Zurich, fleeing the intensified persecution of socialists in Germany.

In 1882, the Zetkins moved to Paris, where Osip and Clara continued to engage in party activities. They made a living by translating and publishing in social democratic newspapers, although the pay was meager. At the time of the death of Osip, who died in 1889 from tuberculosis, he and Clara had two sons. Despite the fact that Clara had been signing the surname Zetkin for many years, she never entered into an official marriage with Osip.

Living in France, Clara Zetkin actively participated in the preparation and work of the Founding Congress of the 2nd International in Paris in 1889, where she gave a speech on the role of women in the revolutionary struggle. And after the persecution of the Social Democrats was stopped in Germany, Klara returned to her homeland, where, since 1892, in Stuttgart she began to publish the SPD newspaper for women, Equality.

In 1907, Clara Zetkin headed the women's department created under the SPD, where, together with Rosa Luxembourg, she campaigned for the equal rights of women. At the International Conference of Women Socialists in Copenhagen in 1910, at the suggestion of Zetkin, it was decided to celebrate International Women's Day, later timed to coincide with the anniversary of the demonstration of New York textile workers on March 8, 1857.