The Muslim Brotherhood's reemergence as a political force coincided with the proliferation of Islamic groups. Some of these groups espoused the violent overthrow of the government while others espoused living a devout life of rigorous observance of religious practices. It is impossible to list all the Islamic groups that emerged in the late 1970s because many of them had diffuse structures and some of the more militant groups were underground. Egypt's defeat and loss of territory in the June 1967 Six-Day War was the main cause for the growth of religiously inspired political activism. Muslims tended to view the humiliating experience as the culmination of 150 years of foreign intrusion and an affront to their vision of a true Islamic community. Islamic tradition rejected the idea of non-Muslims dominating Muslim society. Such a state of affairs discredited Muslim rulers who permitted it to persist. It was, therefore, incumbent on believers to end the domination and restore the true supremacy of Islam. As part of their Sunni creed, the most radical activists adopted jihad and committed themselves to battling unbelievers and impious Muslims. During the 1970s and 1980s, Islamists perpetrated a number of violent acts, including the assassination of Anwar Sadat in October 1981.