Born in London in 1902, the eldest of three children, Heyer spent her early life living in Paris with her parents, George and Sylvia, and her brothers, Boris and Frank. The family returned to England at the outbreak of World War I in 1914, her father serving in the British Army and eventually being awarded an MBE. It was originally to amuse her brother Boris that Heyer wrote what was to be her first published novel, The Black Moth, begun when she was just 17. Her father encouraged his talented daughter, eventually finding a publisher for the book, which was released in 1921. This was the beginning of a literary career that spanned more than five decades.

A year before The Black Moth was published, Heyer had met her future husband, Ronald Rougier. She had become acquainted with him while on holiday with her family, when he was studying to become a mining engineer, and five years later they were married. By this time she had already published five novels, although she had yet to achieve the kind of popularity that characterised her later work. 1925 was important for Heyer in another way, too: her father died of a heart attack in June.

His help and support had enabled her to launch her career as a writer, but George Heyer did not live to see his daughter’s first major success. These Old Shades did not have the most auspicious of starts: published during the General Strike of 1926, it received no newspaper coverage, reviews or advertising. Nevertheless, it met with great enthusiasm from the public, selling 190,000 copies and firmly establishing her name. From then on she refused to give interviews, promote her books or publicise herself in any way, saying ‘my private life concerns no one but myself and my family’.

Cotillion was published in 1953 and, like all her novels, it is characterised by meticulous attention to detail and an encyclopaedic knowledge of the language, manners and dress of the Regency period. It weaves real events and people into the plot with unerring accuracy – a hallmark of her work. She was careful to a painstaking degree: referring to An Infamous Army (1937), featuring the Duke of Wellington, she stated that she attributed no words to him which he had not spoken or written in real life. She even went so far as to purchase one of his letters so that she could copy his verbal style more closely. Much of her time and money were spent chasing up original sources and rare books to add ever greater realism to her work, and she owned a huge library of works on the period.

Although not explicitly stated in the book, it is clear that Cotillion is set in 1816: Heyer mentions several historical events which make it possible to pinpoint the date exactly. For example, during their mock engagement Kitty and Freddy go to see the Elgin Marbles at Burlington House, now the Royal Academy. They were exhibited there in 1816 before being purchased by the British government and moved to the British Museum later that year, where they have remained ever since. Freddy mentions the ‘deuce of a dust’ which the Marbles stirred up: Elgin was heavily criticised by many contemporaries for taking the Marbles from Athens, creating a debate which still continues today. And Lord Buckhaven, Freddy’s brother-in-law, is described as being away on Lord Amherst’s ‘Chinese mission’. William Amherst, First Earl of Amherst (1773–1857), was sent in 1816 as Ambassador Extraordinary to the court of China’s Qing Dynasty on a diplomatic mission. When the mission failed, the party returned home (it was shipwrecked on the way and did not reach England until 1817).

Many of the places which Heyer uses as locations in Cotillion are also authentic: Almack’s, White’s, Bullock’s Museum and Grafton House, to name a few. Grafton House, a popular Bond Street linen-draper’s shop, is actually mentioned in Jane Austen’s letters. She wrote: ‘the whole Counter was thronged and we waited full half an hour before we could be attended to’, echoing the experience described in Heyer’s novel. Clubs were also an important part of upper-class Regency life: Freddy’s father is a member of White’s, the exclusive gentleman’s club in St James’s; his cousin Jack gambles at Watier’s, which eventually closed its doors in 1819, having garnered a reputation as a haven for card cheats; and Almack’s Assembly Rooms, one of London’s first mixed-sex clubs, makes its appearance in many of Heyer’s books. Founded in 1765, it became the most exclusive social venue in London. Admission was decided by the ‘Patronesses’, and their seal of approval guaranteed acceptance into the ton (Regency high society). Heyer’s knowledge of the period was so assured that she only needed to mention places, people and events in passing to anchor her work in an accurate historical backcloth. This odd juxtaposition of meticulous accuracy and lighthearted romance is what set her work apart.

Although vastly popular, Heyer herself was rather cynical about her success. Speaking of Friday’s Child in 1943 she said:

Spread the glad tidings that it will not disappoint Miss Heyer’s many admirers. Judging from the letters I’ve received from obviously feeble-minded persons who do so wish I would write another These Old Shades, it ought to sell like hot cakes. I think myself I ought to be shot for writing such nonsense, but it’s questionably good escapist literature and I think I should rather like it if I were sitting in an air-raid shelter, or recovering from flu. Its period detail is good; my husband says it’s witty – and without going to these lengths, I will say that it is very good fun.