Harriet Westbrook was born on 1 August 1795 in London, England. Her father was the highly successful owner of a coffee house in Grovesnor Square. Harriet was sent to a girls' school in Clapham, where she became a friend to Hellen Shelley, the younger sister of Percy Bysshe Shelley. In 1811, Harriet and Percy elloped to Scotland. A daughter, Eliza Ianthe, was born to Shelley and Harriet in June 1813, but the marriage was becoming strained. Though they remarried in March 1814, to ensure Harriet's and Eliza's legal status, a few months latter Percy started his relationship with Mary Wollstonecraft Godwin. Despite this, in November 1814, Harriet gave birth to a son, Charles. By 1815 Harriet and Percy Shelley were living completely seperately, though Percy still helped financially supported Harriet and their children. While Harriet was financially secure, she was clearly unhappy. For a period, she returned to her father's house, but found it overly constraining. At some point in 1815 or early 1816, Harriet took a lover, possibly a military officer in Chelsea. In the Summer of 1816, she moved to lodgings in Knightsbridge, most likely to hide her pregnancy from her family. By December, Harriet was heavily pregnant and living alone, believed to be abandon by her lover. On 10 December 1816, Harriet Shelley was found dead in the Serpentine, a lake in Hyde Park. she left a heart-rending note, probably written on 7 December, intended for Shelley, her parents, and her sister Eliza, in which she expressed her wish that Percy to take custody of their son Charles, but that Ianthe should be brought up by Eliza.