Liberian President William R. Tolbert Jr., 66 who was assassinated Saturday in what has been reported as a coup led by Army enlisted men, had been president of his west African nation since 1971.

President Tolbert was shot three times in the head by a band of soldiers who broke into the executive mansion at 1 a.m., according to news reports. The coup was the first to topple a government of Liberia.

The coup came nearly a year after riots swept Monrovia, the capital of Liberia, when the government decreed increases in the price of rice, the country's staple food.

President Tolbert was a wealthy businessman who in addition to owning and operating a rubber plantation and serving on the board of a fishing and refrigeration company, also had an interest in businesses that benefitted from the increase in the price of rice.

During his years as president of Liberia, he gained a reputation as a force of progressive change and development in his own country and as a conciliator in Africa at large. At the time of his death he was chairman of the Organization of African Unity.

Just last week he had submitted a peace plan to warring factions in Chad. Other forays into international relations had included efforts to help mediate between factions fighting for control in the old Spanish Sahara, and meetings in Monrovia with South African officials concerning the future of Namibia.

He reemphasized Liberia's "special relationship" with the United States, but also established diplomatic relations with the Soviet Union and Czechoslovakia.

President Tolbert said that Liberia would "waltz to no foreign rhythm of flirtatious expedience but would dance instead, with steadfast grace, to the African drums of age-long passions."

President Tolbert came to office following the death of his predecessor, William V. S. Tubman, in 1971. President Tolbert, who had been vice president for 20 years, marked the beginning of a new era at his official inauguration on Jan. 3, 1972.

Instead of the formal attire favored during the Tubman years, President Tolbert was inaugurated wearing a blue cotton shirt and trousers.

The changes continued as President Tolbert dismissed corrupt cabinet officers, encouraged greater freedom of the press and lowered the voting age to 18. He also sold the presidential yacht and replaced the official Cadillac limousine with a Volkswagen.

He inaugurated a social security fund and unemployment compensation and pushed the construction of schools and medical facilities. He also made suprise visits to government offices and installations that never before had seen a president, including one to a prison, where he ordered sweeping changes after tasting the prisoners' food.

His economic policy for Liberia included increased attention to agriculture, in an effort to lessen Liberia's reliance on food imports, exploitation of lumber, and pressure on foreign exporters of iron and rubber to hire and train more Africans and pay higher taxes.

President Tolbert told Time magazine in 1973, "we don't want a classless society, but we must narrow the gulf between the too few who are high and the too many who are low."

The origin of Liberia stems from an 1816 charter granted by the United States Congress to a group called the American Colonization Society. The society's aim was to settle arrived in 1822. Liberia declared itself an independent republic in 1847.

Although the "Americo-Liberians," as they came to be called, were a distinct minority in Liberia (they account for about three percent of today's population) they dominated Liberia's government, business life, and the Army's officer corps.

President Tolbert was born in Bensonville, Liberia, on May 13, 1913. His father came to Liberia from South Carolina about 1880 and became a prosperous coffee and rice grower -- a member of Liberia's elite.

The future president graduated summa cum laude from the University of Liberia in 1934 with a bachelor's degree in liberal arts. In addition to working in the family businesses he was ordained a Baptist minister.

He bagan his government career as a typist with the national treasury, than served as disbursing officer for the government before winning election to the House of Representatives in 1943. He became vice president of Liberia in May 1951, a post he held until taking over the presidency.

From 1965 to 1970, he was president of the Baptist World Alliance. Prior to that he had been president of the Liberia Baptist Missionary and Educational Convention.

In 1936 he married Victoria David, daughter of an associate justice of Liberia's Supreme Court. News accounts report that she is now in jail. Other survivors include two sons and six daughters.