Teacher, journalist, anarchist, feminist and mother of Frederica Montseny. In 1886 at the age of 22, she founded the first secular school in Spain in Vilanova i la Geltrú and was a member of the Teachers’ Confederation of Catalonia.
As a journalist and thinker, she signed her texts with the name Soledad Gustavo. She stood out for her activism in the main struggles of the early twentieth century. She and her husband, Joan Montseny, issued the literary publication Revista Blanca (1898 - 1905 and 1923 - 1936). Writers like Unamuno, Pío Baroja and Francesc Pi i Margall contributed to the publication. In her lectures and in publications like ‘El amor libre’ and ‘La sociedad futura’, she was a steadfast defender of a more egalitarian society, women's emancipation and free love. She also conducted research and campaigns to secure the release of those imprisoned in the Canvis Nous case and in defence of Francesc Ferrer i Guàrdia.
As a journalist and thinker, she stood out for her activism in the main struggles of the early twentieth century. In 1886 she co-founded the first secular school in Spain, and throughout her lifetime, she wrote in a variety of libertarian magazines.