John Grier Varner was born in 1905 in Mount Pleasant, Texas and was raised in Denton. In 1926 he received a B.A. from Austin College. He taught for four years at boys preporatory schools in Mississippi and Tennessee before studying American Literature in graduate school at the University of Virginia. This is where Varner met his future wife Jeannette Johnson, a Montgomery, Alabama native. Jeannette had received her B.A. and M.A. in Romanic Languages and English at the University of Alabama and was pursuing her Ph.D in Spanish and French at the Univerity of Virginia. The Varners were married and John received his master's and doctorate degrees and took a position as Assistant Professor of English and Director of Musical Activities at Washington and Lee University in 1938. Jeannette received her Ph.D. and taught Spanish at Fairfax Hall Junior College for Women in Waynesboro, Virginia.

During World War II John Varner joined the State Department and was sent to Venezuela because of his knowledge of Spanish. From 1944-1947 he was director of the Centro Venezolano-Americano in Caracas. Jeannette taught English and Spanish there and served as the librarian for the center, and the couple also spent these three years touring and lecturing all over the area. Together they published Inglés Moderno, grammar books for students of English. In 1947 John was hired to the U.S. Embassy in Mexico City and also joined the staff of the University of Texas at Austin as Visiting Associate Professor of English and Director of English for Foreign Students.

The Varners settled in Austin a few years later where John continued his professorship with the Department of English and Jeannette became head reference librarian with the Austin Public Library. They spent their free time doing historical and literary research, and they began to publish a number of works about the conquest and settlement of Latin America. Their first book, The Florida of the Inca (1951), was an edited translation of Garcilaso de la Vega's account of the DeSoto expedition. Notably, it was the first publication of the Universtiy of Texas Press and received much scholarly acclaim. In 1954 the Varners traveled to Spain to conduct research for a biography on Garcilaso de la Vega. It was eventually published in 1968 by the University of Texas Press as El Inca: the Life and Times of Garcilaso de la Vega . John Varner retired from teaching in 1972 due to health concerns but continued his scholarly projects at home with his wife. They worked extensively on a book about the Spaniards' use of canines to conquer the Indian empires of America and had finished the draft when John Varned passed away in 1978. Jeannette Varner completed the project and Dogs of the Conquestwas published in 1983 by the University of Oklahoma Press.