The dissertation provides an edition of and a commentary on letters written by Kata Dalström (1858-1923) - Sweden's most well-known female socialist agitator - to Hjalmar Branting (1860-1925), leader ofthe Social Democrat party, and Fredrik Ström(1880-1948), one oft he leaders of the party's youth section. The number of letters to Branting - written in theyears 1895-1916 are 33. The 239 lettersto Ström, which cover the major part of the edition, are written 1905-1923. The letters cast light on the part playedb y Kata Dalström in the spread of Socialist ideas in Sweden, and on her attitude to the Social Democrat party. An introduction presents Kata Dalström’s road to Communism and her dispute with the Social Democrats.