I Now Pronounce You Knight and Knight

The 21st-century social and political trend of same-sex civil unions has roots that go back a bit beyond Stonewall—to the Middle Ages. A history professor who analyzed legal documents and gravesites says medieval law was flexible enough to allow for a variety of non-nuclear family structures, including gay unions, LiveScience reports.

French men could enter an affrèrement—roughly, "brotherment"—to join their homes and property. "I suspect that some of these relationships were sexual, while others may not have been," says the professor, whose work appears in the Journal of Modern History. "It is impossible to prove either way and probably also somewhat irrelevant to understanding their way of thinking." (More gay marriage stories.)