Historian John Boswell’s seminal book on the roots of gay marriage, Same-Sex Unions in Premodern Europe, comes out for the first time in a digital edition next month. The timing seems perfect in the wake of the death of DOMA and Prop 8, though Boswell himself died from complications from AIDS before he saw that momentous day.

Author Annalee Newitz profiles Boswell, a Yale scholar and religious Catholic, as well as his work on i09. Newitz recalls how Boswell dedicated the majority of his scholarly life to researching the late Roman Empire and early Christian Church which yielded some remarkable findings:

There were dozens of records of church ceremonies where two men were joined in unions that used the same rituals as heterosexual marriages. (He found almost no records of lesbian unions, which is probably an artifact of a culture which kept more records about the lives of men generally.)

The poor lesbians — always getting the figurative shaft, for lack of the literal. Anyqueer, Boswell argued that the Church tried to sweep these same-sex unions under the holy rug and redefined marriage — sound familiar — in the 13th century “to be for the purpose of procreation,” as conservatives loudly like to remind us at every turn. But if the Church — not to mention the Oxford Dictionary — can redefine marriage once, what’s wrong with doing it again?

The unions, Newitz points out, don’t necessarily fit the definition of marriage we have today. Taboos against homosexuality, which as a social construct is relatively new (the love that dared not speak its name went unnamed until the late 19th century), as well as the original purpose of matrimony — wealth/land sharing — have changed over time. But many of these unions in Boswell’s research involved the love of two people of the same-sex, which were in turn consecrated by the Christian Church.

So next time someone starts mouthing off about redefining marriage, politely remind them that every few hundred years or so, ancient institutions like to be shaken up a little.