On 6 October 1973, in conjunction with Hafez al-Assad of Syria, Sadat launched the October War, also known as the Yom Kippur War (and less commonly as the Ramadan War), a surprise attack against the Israeli forces occupying the Egyptian Sinai Peninsula, and the Syrian Golan Heights in an attempt to retake these respective Egyptian and Syrian territories that had been occupied by Israel since the Six Day War six years earlier.