POSSIBLY no figure in Arab history has been more honored and more vilified than Anwar Sadat. Within Egypt and in many countries around the world, the death of Mr. Sadat was mourned as a blow to the cause of peace. But his Arab opponents greeted the news with jubilation. A man of unique qualities, Sadat did more than any other individual in modern history to change Western concepts of the Arab people. He was widely viewed as a moderating influence and stabilizing force in the volatile Middle East. Even many who publicly disagreed with him privately admired his courage and conviction. Anwar Sadat was born on December 25, 1918, in the poor Nile Delta village of Mit Abul Kom. The nearest bus route was a mile away. In his 1978 autobiography In Search of Identity, he proudly called himself "a peasant born and brought-up on the banks of the Nile." Sadat's father was a civilian clerk in the army. His mother was part Sudanese. The family eventually moved to Cairo and Sadat entered the Royal Military Academy, graduating in 1938. One of his classmates was Gamal Abdel Nasser. During World War II, Nasser and Sadat became friends. They were active during the war in the pro-German underground. Sadat was imprisoned for his anti-British activities. After the Allied victory, Sadat resumed efforts against British colonial domination in Egypt. He was twice jailed for involvement in plots against royalist politicians in Egypt but was acquitted both times. Released from jail in 1948, he drove a truck and worked as a journalist. Regaining his captain's rank in the Egyptian army in 1950, Sadat and eight other officers, including Lieutenant Colonel Nasser, began plotting the overthrow of King Farouk and the final ouster of the British from Egypt. The nine men led what became known as the Free Officers Movement, with secret cells planted throughout the Egyptian military. Sadat was a member of the Military Command Council that seized control of Egypt on the night of July 22, 1952. The revolution led to the exile of Farouk and the emergence of Nasser as strongman and president. Sadat held a number of jobs under President Nasser, including secretary general of the Islamic Congress, 'editor of the government daily Al Gomhouria and president of the National Assembly. Sadat was not as visible as some-other "free officers" around Nasser. But he endured and above all, he was loyal. Finally, less than 10 months before Nasser died, he named Sadat vice president. On September 28, 1970, Nasser died of a heart attack, leaving a void few thought could be filled. Into the void stepped Anwar Sadat, a virtually unknown personality outside Egypt. Many saw him as merely a caretaker president. "We're suffering two plagues at one time," one joke went. "First Nasser dies. Then we get Sadat." Sadat, however, quickly set about forming his own policies for a stronger and more independent Egypt and establishing a firm personal leadership. In July, 1972, Sadat abruptly ordered the withdrawal of thousands of Soviet advisers from Egypt and started turning Egypt's orientation from the Soviet Union to the United States. This represented a radical departure from Nasser's longstanding pro-Soviet stance. Sadat later wrote, "I wanted to tell the whole world that we are always our own masters." In 1973 Sadat led Egypt in what he described as a "glorious Arab victory" in the October 6 War against Israel. He sent his troops storming across the Suez Canal in an operation that caught the Israelis by surprise. Though ultimately defeated militarily, Egypt had scored an enormous psychological victory. The war did much to rebuild national self-respect that had been severely shaken in the disastrous Six-Day War of 1967. Egyptians hailed Sadat as a hero. In 1974 Sadat launched a policy of economic liberalization that led to invitations to European and U.S. companies to do business in Egypt. Despite these moves, Egypt was still plagued with a desperately poor economy. In a nation of 38 million people, with one fourth concentrated in the teeming capital of Cairo and the rest spread out on narrow strips of fertile land along the Nile, per capita income was only $250 a year. The cost of maintaining a battle-ready army of 300,000 men left few funds for Egypt's development. In November, 1977, Sadat stunned the world when he declared he would go to the ends of the earth, "even to the Israeli Knesset [parliament]," to discuss peace if it would save even one Egyptian soldier. Less than two weeks later, Sadat was in Israel, electrifying his own nation and horrifying most other Arab leaders. He became the first major Arab leader to proclaim his willingness to accept Israel's existence as a sovereign state. The trip totally shattered Arab precedent. Sadat's visit to Israel culminated in the 1978 U.S. - mediated Camp David Accords and a peace treaty with Israel signed on March 26, 1979, in Washington. The treaty ended three decades of conflict between Egypt and the Jewish state. With Israeli Prime Minister Menachem Begin, Sadat was a joint winner of the 1978 Nobel Peace Prize. While making peace with his old enemy, Sadat made enemies of many former allies. Hardline Arab states, condemning Sadat as a "traitor to the Arab cause" and a "pawn of Zionism," blackballed him from the Arab community. Their response stemmed from the fact that the treaty did not provide a timetable for full self-determination for the West Bank Palestinian Arabs, leading eventually to an independent Palestinian State. Libyan-Ieader Colonel Moammar Khadafy, Egypt's western neighbor, was one of Sadat's harshest critics. Sadat nevertheless persevered in his conviction that his was the best route both for Egypt and for the region as a whole. That conviction eventually brought about his death. Sadat was well-educated and had taught himself English, French, German and Persian. He spoke in wonderful resonant tones. His dazzling smile came across well on television, where he used his rural roots to build a "man of the people" image. Many say Sadat's subtle elegance was due to his half-English second wife, Jihan, by whom he had three-daughters and a son. The beautiful and aristocratic-looking Mrs. Sadat became something of a rarity in the Arab world, an aggressively public woman who played an active role in public affairs and championed a new role for women and other liberal causes. President Sadat's assassination on the eighth anniversary of the October 6 War raises new uncertainty about the future of the Middle East. The long-range geopolitical effects of his departure will be major.