In September 1970 King Hussein of Jordan drove the Palestine Liberation Organization out of his country. On 18 September 1970, Syrian tanks invaded Jordan, intending to aid the PLO. At the request of the US, Israel moved troops to the border and threatened Syria, causing the Syrians to withdraw. The centre of PLO activity then shifted to Lebanon, where the 1969 Cairo agreement gave the Palestinians autonomy within the south of the country. The area controlled by the PLO became known by the international press and locals as "Fatahland" and contributed to the 1975–1990 Lebanese Civil War. The event also led to Hafez al-Assad taking power in Syria. Egyptian President Nasser died of a heart attack immediately after and was succeeded by Anwar Sadat.