In 1979, two events occurred which the Al Saud perceived as threatening the regime, and had a long-term influence on Saudi foreign and domestic policy. The first was the Iranian Islamic revolution. There were several anti-government riots in the region in 1979 and 1980. The second event was the seizure of the Grand Mosque in Mecca by Islamist extremists. The militants involved were in part angered by what they considered to be the corruption and un-Islamic nature of the Saudi regime. Part of the response of the royal family was to enforce a much stricter observance of Islamic and traditional Saudi norms. Islamism continued to grow in strength.