Two ancient skeletons buried hand-in-hand, known as the Lovers of Modena , were both men, according to new research.
The pair, who are believed to have died between the 4th and 6th centuries, had previously been thought to be a male and a female.
But researchers from the University of Bologna in Italy used a new technique to determine their gender by analysing proteins in their tooth enamel.
"Upon discovery, mass media had immediately assumed they were a male-female couple, even if bad preservation of the bones did not allow an effective sex classification," according to the paper, which was published in the Nature research journal .
The way the pair were laid to rest "represents a voluntary expression of commitment between two individuals" and was not a common burial practice, it added.
They were discovered in 2009 in the Ciro Menotti necropolis in Modena alongside 11 other skeletons, some of which showed signs of injuries that were likely to have been sustained during war.
The two "lovers" could therefore have been "war comrades or friends, died together during a skirmish and, thus, buried within the same grave", according to researchers.
They added that the burial was a "unique representation of commitment between two men" during the period.
They could also have been family members, the researchers said, and while it could not be ruled out that the pair were lovers it was unlikely they would have been buried hand-in-hand because of attitudes to homosexuality at the time.
The discovery of the skeletons' gender could have "profound implications" for understanding burial practices in Late Antique Italy, according to the authors.
