From the 1890s onwards, Angola became one of the destinations for anarchists that had been exiled by successive Portuguese governments, possibly resulting in the development of a syndicalist presence in the colony. Following the 28 May 1926 coup d'état, Portuguese anarchists participated in a failed revolt against the new military dictatorship, after which the General Confederation of Labour (CGT) was outlawed. As a result, in October 1927, the CGT leader Mário Castelhano was himself deported to Angola, where he stayed for two years, before making his way back to Portugal. In the wake of the Portuguese general strike of 1934, the Estado Novo established a concentration camp on the north bank of the Kunene River, to which they deported some anarcho-syndicalists that were involved in the strike.