In the lofty drawing rooms and oak-panelled libraries of Britain's stately homes and castles, revolution is afoot. The change in the law allowing first-born girls to succeed to the throne, hastened by the Duchess of Cambridge's pregnancy, has triggered calls for similar equality to be introduced across the aristocracy.
Last week ministers rushed out new legislation to ensure that if Prince William and the Duchess of Cambridge's baby is a girl, she can become Queen. But there is now an intense debate about whether daughters of the landed gentry should be able to lay claim to their fathers' dukedoms or earldoms.
Lady Clare Kerr, the elder daughter of the veteran Tory politician Michael Ancram, the Marquess of Lothian, will not inherit her father's title. She has a sister, but no brothers, meaning the marquessate goes to their uncle.
Lady Clare said she did not wish the law changed for herself, but said the aristocracy was now "two steps behind" the Royal Family because, even before the proposed legislation, daughters can still inherit the throne if there are no sons.
In the case of the majority of titles in the British peerage, there must always be a male heir for the line to continue, even if the nobleman only has daughters. Lady Clare, who is married to the Cabinet Office minister Nick Hurd, said there were good reasons for the male-only rule to exist to protect names and families.
But she told The Independent on Sunday: "There is certainly a conversation to be had with regard to moving even one step forward to where the Royal Family were before this recent change; in the absence of a son there should be no reason a daughter should not inherit – and once that has been established it is difficult to argue against girls inheriting if they are the first-born."
Lady Clare, 33, has a seven-month-old daughter with her husband, whose department is overseeing the changes to the royal succession law. She added: "There are more pressing issues demanding the attention of the Government – but I am wholly supportive of equal rights.
The writer and artist Lady Liza Campbell, 53, whose elder sister missed out on the earldom of Cawdor, which went to their younger brother, was more forthright. She said: "There's no reason why an older sister should be passed over for a younger brother. Most of the reasons for opposing it are nonsense. Like talk of bloodlines not being carried over – blood flows in women's veins too.
"It's a massive anomaly that this nonsense is still continuing, especially when the current monarch is a Queen. Women have been enfranchised for almost 100 years and yet still they get passed over within their own families. It gives talk of universal equality a tinny ring."
The 10th Earl of Jersey, William Villiers, 36, is married with three daughters, but has no son, meaning his titles and estate will pass to his younger half-brother, Jamie Villiers, now 18, the only son of his father's third wife. He said he would welcome a compromise where, if there was no son, a daughter could inherit. "My heir at the moment is my half-brother, and in my eyes that isn't right. My half-brother's appreciation of it all is different. He hasn't grown up surrounded by the history, as my daughters have. His experience of it is more diluted. My daughters would be more akin to it than him... But it's a very divisive issue."
Charles Kidd of Debrett's Peerage said there would need to be a change in the law to allow aristocratic titles to pass to girls, adding: "It seems likely that there will be some discussion about women inheriting hereditary peerages which at present may only pass in the male line."
Daughters who are missing out
Lady Sophie Nevill, 22, is the only child of the 6th Marquess of Abergavenny, Christopher Nevill. Her twin brother died in infancy. A singer who goes by the stage name of Sophie Trilby, she would have inherited Eridge Park, a stately home in East Sussex, as well as land in Kent, if she had been a boy. As there is no male heir apparent to the current Marquess, his title and that of Earl of Lewes will die out with him.
Lady Violet Manners, 19, is the eldest of the three daughters of the Duke of Rutland. The heir is their younger brother, Charles, the Marquess of Granby, 13. He will inherit Belvoir Castle, Leicestershire, Haddon Hall in Derbyshire, 15,000 acres of land and an estimated wealth of £125m.
Lady Lara Katrina Compton, 44, will miss out to her younger brother Daniel, Earl Compton, on becoming Marquess of Northampton when their father, Spencer Compton, 66, dies. The title comes with a stately home, Castle Ashby in Northamptonshire, land in Warwickshire, property in Islington, north London, and an estimated wealth of £120m.
Lady Louisa Trotter, 30, is the eldest child of the Duke of Buccleuch and Queensberry. Her younger brother, the Earl of Dalkeith, 28, a former page of honour to the Queen, inherits the twin dukedoms on their father's death. The title comes with three houses including Drumlanrig Castle in Dumfries and Galloway and 240,000 acres of land, making the duke the largest private landowner in the UK.