Princeton Lyman, a career diplomat who served as U.S. ambassador to Nigeria and later to South Africa, where he helped engineer the transition from the country’s apartheid era of white supremacy to a multiracial, democratically elected government in the 1990s, died Aug. 24 2018 at his home in Silver Spring, Md. He was 82. joined the Foreign Service in 1961 and was assigned to the newly formed U.S. Agency for International Development. He lived in Korea in the 1960s, then turned his primary attention to Africa, serving as USAID’s program director in Ethiopia in the 1970s and as U.S. ambassador to Nigeria from 1986 to 1989. He achieved his greatest diplomatic breakthroughs in South Africa, where he was ambassador from 1992 to 1995. Princeton Nathan Lyman was born Nov. 20, 1935, in San Francisco. His parents were Jewish immigrants from Lithuania who ran a corner grocery store in a largely African American neighborhood. His parents valued education and named four of their five sons after universities: Harvard, Yale, Stanford and Princeton. (Another son was named Elliott, and a daughter was named Sylvia.) Dr. Lyman graduated from the University of California at Berkeley in 1957 and received a doctorate in political science from Harvard University in 1961. Dr. Lyman was the State Department’s director of refugee affairs from 1989 to 1992. After returning from South Africa, he was the State Department’s chief liaison to the United Nations, working closely with Secretary General Kofi Annan, who died Aug. 18. After retiring in 1999, he held posts at the Aspen Institute, U.S. Institute for Peace and Council on Foreign Relations. His first wife, the former Helen Ermann, died in 2008 after 50 years of marriage. Survivors include his wife since 2009, Lois Hobson of Silver Spring; three daughters from his first marriage, Tova Brinn of Safed, Israel, Sheri Laigle of Silver Spring and Lori Bruun of Columbia, Md.; a brother; a sister; 11 grandchildren; and two great-grandsons.