John Eastburn Boswell (March 20, 1947 – December 24, 1994) was a prominent historian and a professor at Yale University. Many of Boswell's studies focused on the issue of homosexuality and religion, specifically homosexuality and Christianity. Opinions are sharply divided regarding the quality of his work, but I (William A. Percy) believe that Boswell was the most successful quack in gay medieval studies in the past generation.
In Christianity, Social Tolerance and Homosexuality (1980), Boswell argued that the Roman Catholic Church had not condemned gay people throughout its history but, at least until the twelfth century, had alternately evinced no special concern about homosexuality or actually celebrated love between men. The book won the American Book Award for History and the Stonewall Book Award in 1981, but it was criticized by scholars, including Warren Johansson and Wayne Dynes, who believed that he had attempted to whitewash the historic crimes of the Christian Church against gay men.
Boswell helped organize and found the Lesbian and Gay Studies Center at Yale, which is now the Research Fund for Lesbian and Gay Studies.
For another point of view, see Mathew Kuefler et. al., The Boswell Thesis: Essays on Christianity, Social Tolerance, and Homosexuality