The date came from the brutal 1961 assassination of the three Mirabal sisters, political activists in the Dominican Republic, on orders of Dominican ruler Rafael Trujillo (1930-1961). On 17 December 1999 by resolution 54/134, the General Assembly designated 25 November as the International Day for the Elimination of Violence against Women, and has invited governments, international organizations and NGOs to organize on that day activities designated to raise public awareness of the problem. Women’s activists have marked 25 November as a day against violence since 1981.
For more information and further links visit http://www.un.org/depts/dhl/violence/