Lord Ivar Mountbatten and partner James Coyle

Washington - Ordinarily, the wedding of a junior member of the British royal family wouldn't attract much global attention. But Lord Ivar Mountbatten's has.

That's because Mountbatten, a cousin of Queen Elizabeth II, is expected to wed James Coyle this summer in what has been heralded as the "first-ever" same-sex marriage in Britain's royal family.

Perhaps what makes it even more unusual is that Mountbatten's ex-wife, Penny Mountbatten, said she will give her former husband away.

Who says the royals aren't a modern family?

Though Mountbatten and Coyle's ceremony is expected to be small, it's much larger in significance.

"It's seen as the extended royal family giving a stamp of approval, in a sense, to same-sex marriage," said Carolyn Harris, historian and author of Raising Royalty: 1000 Years of Royal Parenting. "This marriage gives this wider perception of the royal family encouraging everyone to be accepted."

But the union isn't believed to be the first same-sex relationship in British monarchy, according to historians. And they certainly couldn't carry out their relationships openly or without causing intense political drama within their courts.

Edward II, who ruled from 1307-1327, is one of England's less fondly remembered kings. His reign consisted of feuds with his barons, a failed invasion of Scotland in 1314, a famine, more feuding with his barons, and an invasion by a political rival that led to him being replaced by his son, Edward III. And many of the most controversial aspects of his rule - and fury from his barons - stemmed from his relationships with two men: Piers Gaveston and, later, Hugh Despenser.

The speculation that Edward II's relationships with these men went beyond friendship was fueled by Christopher Marlowe's 16th-century play Edward II, which is often noted for its homoerotic portrayal of Edward II and Gaveston.

James VI and I, who reigned over Scotland and later England and Ireland until his death in 1625, attracted similar scrutiny for his male favourites, a term used for companions and advisers who had special preference with monarchs. Though James married Anne of Denmark and had children with her, it has long been believed that James had romantic relationships with three men: Esmé Stewart, Robert Carr and George Villiers, Duke of Buckingham.

Correspondence between James and his male favorites survives, and as David M. Bergeron theorizes in his book King James and Letters of Homoerotic Desire: "The inscription that moves across the letters spell desire."

James was merely 13 when he met 37-year-old Stewart, and their relationship was met with concern.

A lost portrait of Buckingham by Flemish artist Peter Paul Rubens was recently discovered in Scotland, depicting a striking and stylish man. And a 2008 restoration of Apethorpe Hall, where James and Villiers met and later spent time together, discovered a passage that linked their bedchambers.

One queen who has attracted speculation about her sexuality is Queen Anne, who ruled from 1702-1714. Her numerous pregnancies, most of which ended in miscarriage or a stillborn child, indicate a healthy relationship with her husband, George of Denmark.

And yet, "she had these very intense, close friendships with women in her household," Harris said.

Most notable is her relationship to Sarah Churchill, the Duchess of Marlborough, who held enormous influence in Anne's court as mistress of the robes and keeper of the privy purse. She was an influential figure in Whig party politics, famous for providing Anne with blunt advice and possessing as skillful a command of politics as her powerful male contemporaries.

Whether Churchill and Queen Anne's intense friendship became something more is something we may never know. "Lesbianism, by its unverifiable nature, is an awful subject for historical research and, inversely, the best subject for political slander," writes Ophelia Field in her book Sarah Churchill: Duchess of Marlborough: The Queen's Favourite.