The article deals with the aspect of Irish history, poorly explored by historiography. This aspect is devoted to the activities of the members of the Irish Republican Brotherhood (the so-called Fenians) from 1868 till 1882. Unsuccessful attempts to organize armed rebellion and the repressions from London forced the Fenian organizations to reconsider and reshape their tactics, aimed at achieving independency. The organization experienced the process of decentralization. The author points out that during this period three ways were formed in the depths of the movement. These streams later manifested themselves in the history of the national struggle of the Irish for independence.