Waves of social movements throughout the 1960s began to shape the values of the generation who were students during 1968. In America, the civil rights movement was at its peak, but was also at its most violent, such as the assassination of Martin Luther King Jr. on April 4 by a white supremacist. In Northern Ireland, religious division paved the way for a decades-long violent conflict between Irish republicans and Irish unionists. Italy and France were in the midst of a socialist movement. The New Left political movement was causing political upheavals in many European and South American countries. The Israeli–Palestinian conflict had already started, the British anti-war movement remained strong and African independence movements continued to grow in number. In Poland in March 1968, student demonstrations at Warsaw University broke out when the government banned the performance of a play by Adam Mickiewicz ("Dziady", written in 1824) at the Polish Theatre in Warsaw, on the grounds that it contained "anti-Soviet references". It became known as the March 1968 events.