Homosexuals have long served in the Christian church, their sexual inclinations either ignored or unobserved.
Over the past 30 years however, Christian denominations across the world have started to ordain openly gay men and women - appointments which cause as much controversy today as they did in the 1970s.
BBC News Online looks at some of the key dates in homosexuals' battle to join the priesthood.
1961 - The Vatican declares that all those "affected by the perverse inclination" towards homosexuality must be barred from taking religious vows or being ordained within the Roman Catholic Church.
June 1972 - Reverend William Johnson becomes the first openly gay candidate to be ordained in a Christian institution, the United Church of Christ.
Gene Robinson is not the first to cause controversy
September 1972 - The Evangelical Lutheran Church in the Netherlands becomes the first European Christian denomination to decide that lesbians and gays could serve as pastors. Over the next 30 years it is joined by a dozen other protestant churches on the continent.
1988 - The United Church of Canada authorises the ordination of homosexuals, the first Christian denomination in the country to do so.
1989 - The US Anglican bishop John Spong ordains Robert Williams, a homosexual. Mr Williams later loses his job after denouncing monogamy and making untoward remarks about Mother Theresa.
1994 - The Old Catholic Church of Austria opens the way for gay clergy along with other European Catholic churches which split with Rome in the 19th Century, including those in Germany and the Netherlands.
2000 - Norway's minister of churches upholds the appointment of Jene Torstein Olsen, the first openly gay clergyman hired to preach in the Church of Norway.
The appointment of this gay clergyman sparked an international row
January 2003 - The Vatican's Congregation for Worship publishes an open letter stating: "The ordination to the priesthood of homosexual men, or men with homosexual tendencies, is absolutely inadvisable and imprudent, and from a pastoral point of view, very risky"
June 2003 - An acknowledged homosexual living a celibate life is appointed bishop of Reading, in England. He declines to take up the post after his appointment causes a bitter row within the international Anglican Church.
July 2003 - The Uniting Church in Australia, the country's third largest church, becomes its first mainstream denomination to accept homosexual priests. It also prompts bitter criticism from the Anglican Church.
August 2003 - The rank and file of the Anglican Church in America vote to elect an openly gay bishop, Reverend Canon Gene Robinson of New Hampshire.
Church leaders approve his appointment, but not before allegations of "inappropriate conduct" are made against the reverend, and the vote is postponed while these are investigated and proved unfounded.