Catherine was born in 1700, the only daughter of John Hoskins of Oxted, Surrey, and steward to the Duke of Bedford.
She married William Cavendish (1698-1755), the future 3rd Duke of Devonshire, on 27 March 1718, and the couple went on to have seven children: Caroline, William (4th Duke), George, Elizabeth, Rachel, Frederick, John.
Having succeeded to the Dukedom in 1729, the couple had to contend only a few years later with the fire which destroyed much of their London home, Burlington House.
Catherine’s tenure as Duchess was incredibly long – having succeeded to the title in 1729, she would not be replaced as Duchess until her grandson married Georgiana Spencer in 1774.
Her own son, William, married Lady Charlotte Boyle, daughter of Richard Boyle and Dorothy Savile, in 1748. It was a match to which Catherine was bitterly opposed; however, the Charlotte was to die only six years later.
The Duchess was so opposed to the match that she and her husband temporarily separated, as he was in favour of the marriage; though the Duke and Duchess were eventually reconciled, she never accepted Charlotte.
The Duchess was not of aristocratic heritage, and comments made by Horace Walpole suggests that she was something of a figure of fun in society, writing in the 1750s that:
‘the Duchess of Devonshire has had her secular assembly, which she keeps once in fifty years: she was more delightfully vulgar at it than you can imagine; complained of the wet night, and how the men would dirty the rooms with their shoes; called out at supper to the Duke "Good God! my lord, don't cut the ham, nobody will eat any!" and relating her private menage to Mr. Obnir, she said, "When there's only my lord and I, besides a pudding we have always a dish of Yeast!"
