At the time of struggles for the political character of the Czechoslovak Republic after its establishment on 28th October 1918, the progressive members of the proletariat in the Kladno industrial area decided, regardless of the views of the educational authorities, to set up a school for their children which would bring them up for life in a future socialist State. They called it Free Socialist Labour School and they chose hammer, sickle and pen as its emblem. The Kladno Socialist School was, at the same time, the first Czechoslovak experimental school. Throughout the whole period of its duration in the years 1919— 1933 it tried to proceed, in its internal work, primarily from the children’s interests and activities and to lead the children to independence and to the love of work. The content of education was guiding the pupils in such a way as to make them realize the ideals of socialism and internationalism. The Kladno Socialists declared that their school would be a working class school. By doing so they linked the fate of their school with that of the revolutionary working class. In the first period of its existence (1919—1920), i. e. in the period of rising revolutionary upsurge, the school is active in public life, participates in all political actions and spreads the ideas of a socialist school system in Bohemia and Moravia. After the defeat of the General Strike in December 1920 and in the years that followed, i. e. when capitalism was being consolidated, the school withdraws from public life, and at the order of the authorities drops the word ≫Socialist≪ from its title, but in its internal work it continues to bring up the children for Socialism. The worst period was that following the year 1927 when the strength of the working class was undermined and the great depression bore hard on the proletariat. From the year 1928 onwards the education authorities were trying to close down the school but were cautious enough not to make it a political act. Taking advantage of the reduced pedagogical standard of the school after the removal of some of its teachers as a result of persecution and with the help of several contemporary expert educationalists they declared that the Kladno educational experiment was no more of any use to educational research. The final onslaught on the school was launched in the form of a personal attack on a teacher, Miss Mladá, whose salary was stopped because she had refused to leave the school. After that the school surrendered at last and the Association of Friends carried out its liquidation at the end of the 1932/33 school year.