Jeanne-Antoinette Poisson (1721–1764), also known as Madame de Pompadour, was a member of the French court and the official chief mistress of King Louis XV of France. In childhood she was given the nickname Reinette, "little Queen"; in her later life she went by Madame d'Etoiles and, after separating from her husband, Marquise de Pompadour. (PROSE: The Time Lord Letters)
In her life she was, according to the Doctor, an "actress, artist, musician, dancer, courtesan, fantastic gardener!" To Rose's surprise, Reinette actually got along well with her lover's real wife. (TV: The Girl in the Fireplace)
At the age of nine, (PROSE: A History of Humankind) Jeanne-Antoinette met a Fortune Teller who predicted that she would eventually marry the King. There after she was given the nickname "Reinette" - which means "little Queen". (PROSE: The Show Path...)
The Tenth Doctor met Reinette several times in her life as a result of time manipulation by the Clockwork Droids. The first was in 1727, when she was a child, and they briefly talked through her fireplace, which was a time window between the 18th century and the 51st. Months later, from her perspective, the Doctor visited her in person, and saved her from a Clockwork Droid under her bed. Over the years, she attributed this event to a nightmare, and saw the Doctor as an imaginary friend.
As an adult, Reinette met the Doctor again, realising he was real. After flirting with him, she kissed him for the first time, before having to join her mother. At some point, Reinette and her friend Catherine were talking in the garden about how the queen was ill, and she briefly sensed the Doctor's presence. (TV: The Girl in the Fireplace)
In 1745, Reinette met Louis XV for the first time as a masked ball. (PROSE: A History of Humankind) The Doctor, Rose and Mickey watched the pair through a time window; she flirted with him, but was attacked by another Clockwork Droid. The Doctor saved her with a futuristic fire extinguisher, and discovered that the Droids would answer only to her. Reinette interrogated it as to why they were stalking her, and it revealed they wanted her head to repair their ship, but she was not "complete" yet. After the droid said they were "the same", the appalled Reinette ordered it to leave.
Reinette and the Doctor began to form a romantic relationship. She called the Doctor her "lonely angel". Using his Time Lord abilities, the Doctor examined Reinette's mind to look at her past experiences. It was not long before he realised that Reinette was also using this opportunity to gaze within his own mind, witnessing his lonely childhood. When he asked Reinette how she managed that, she said that "a door once opened may be stepped through in either direction." To comfort him, Reinette took him to the Yew Tree ball, telling him that "every lonely little boy must learn to dance". Afterwards, Reinette went on to become the King's mistress. Despite this, she got on well with the Queen, and was given the title Madame de Pompadour.
At age 32, Reinette was visited by Rose, who told her the Clockwork Droids would come for her in five years time, on her 37th birthday. After Rose explained the Droids were hunting her throughout her life, trying to find her at age 37, as that was the age of the ship, Reinette followed her onto the ship, and heard her future self's screams. Disturbed, she elected to take "the slow path".
On her 37th birthday, as predicted, the Droids attacked, and Reinette was led to the hall by them. She refused to go with them to their ship, so they decided to take her head there and then. Reinette calmly treated them as her childhood nightmare, knowing "their nightmare" would come for them. The Doctor arrived, smashing threw a time window into the hall. This broke the connection to the ship, and the Droids, having failed, all shut down.
When the Doctor was stranded in the 18th century, Reinette sadly showed him that her fireplace still functioned as a way back to the 51st century. The Doctor invited her to travel with him but, due to the time differential, she died before she could do so. In her final days, she wrote a letter to the Doctor, and after her death, as they watched a black cab take her body from Versailles for the last time, the King gave the Doctor the letter. (TV: The Girl in the Fireplace)
Letter to the Doctor
My dear Doctor: the path has never seemed more slow, and yet I fear I am nearing its end. Reason tells me that you and I are unlikely to meet again, but I think I shall not listen to reason. I have seen the world inside your head and know that all things are possible. Hurry though, my love: my days grow shorter now, and I am so very weak. Godspeed, my lonely angel.
In the 51st century, the starship SS Madame de Pompadour was named after her. (TV: The Girl in the Fireplace) Due to the Clockwork Droids scanning her brain, the ship's computer began believing itself to be Reinette. (WC: Pompadour)
When River Song met the Eighth Doctor's companion Helen Sinclair, she advised Helen to have the Doctor take her to Versailles at some point, but advised her to have him avoid meeting Madame de Pompadour, as it would make things complicated. (AUDIO: The Doomsday Chronometer)
Reinette demonstrated intelligence and an open-minded nature in her thinking, accepting both the futuristic world and the fact of the Doctor being an alien. She also showed amazing courage. Instead of running away, she defied the Clockwork Droids and stood up to them, even at blade-point, insisting that the Doctor would come.
Reinette further had great compassion for the Doctor, pitying him for his loneliness. She was sympathetic after looking into his childhood memories. She and the Doctor shared a strong romantic connection with each other. (TV: The Girl in the Fireplace)
Behind the scenes
Information from invalid sources
In Doctor Who: Legacy, the Eleventh Doctor, stressing the importance of preventing the Sontarans' interference in the timeline, cites Madame de Pompadour as an example of an important person in human history whose existence is endangered.