On November 6th, 1895, crowds of curious sightseers gathered outside St Thomas Church on Fifth Avenue in New York intent on spotting a small, dapper bridegroom whom they knew to be a great English aristocrat awaiting his bride-to-be. When she arrived, twenty minutes late, anyone who caught a glimpse beneath her veil would have seen that her face was swollen with crying.

When Consuelo Vanderbilt’s grandfather died he was the richest man in America; the Vanderbilt fortune stood at $200 million. Her father, William K, started to spend it, enthusiastically assisted by Consuelo’s mother, Alva, who was determined to take the family to the top of New York society. She was adamant that her daughter should make a grand marriage and the underfunded 9th Duke of Marlborough was just the thing. It didn’t matter that Consuelo loved someone else; as Alva once told her, ‘I don’t ask you to think, I do the thinking, you do as you are told.’

However, the story of Alva and Consuelo is not simply one of the emptiness of wealth, the glamour of America’s Gilded Age and vaulting social ambition. It is a fascinating study of the way in which both women struggled to break free of the deeply materialistic world into which they were born and took up the fight for female equality. Consuelo threw herself into good works; Winston Churchill encouraged her to make her first public speech, and her social and political campaigns proved an antidote to loneliness. Alva embraced the militant suffragette movement, helping to bring the fight for the vote to its triumphant conclusion and campaigning vehemently for women’s rights until she died. In this compelling and brilliantly acute book, Amanda Mackenzie Stuart suggests that behind the most famous transatlantic marriage of all lies an extraordinary tale of the quest for female power.