The founding congress of CASATU, University of Kwazulu Natal There was an unprecedented level of resistance in factories and black communities in the 1980s over economic and political issues. In fact it was a period in which the highest level of strikes in South African history was recorded. As large-scale political organisations like the UDF emerged it became necessary to form an umbrella federation of trade unions. After protracted negotiations the Congress of South African Trade Unions COSATU was formed in November 1985. At the time of its establishment it had more than 462 000 members and by 1991 this number had grown to more than 1 258 800. The largest proportion of its members came from the manufacturing and mining sectors. The activities of Cosatu became closely linked to the wider liberation struggle. Women like Emma Mashinini were instrumental in its formation. .