English writer Mary Shelley is best known for her horror novel "Frankenstein, or the Modern Prometheus." She was married to poet Percy Bysshe Shelley.

Who Was Mary Shelley? Writer Mary Shelley published her most famous novel, Frankenstein, in 1818. She wrote several other books, including Valperga (1823), The Last Man (1826), the autobiographical Lodore (1835) and the posthumously published Mathilde.

Early Life Shelley was born Mary Wollstonecraft Godwin on August 30, 1797, in London, England. She was the daughter of philosopher and political writer William Godwin and famed feminist Mary Wollstonecraft — the author of The Vindication of the Rights of Woman (1792). Sadly for Shelley, she never really knew her mother who died shortly after her birth. Her father William Godwin was left to care for Shelley and her older half-sister Fanny Imlay. Imlay was Wollstonecraft's daughter from an affair she had with a soldier. The family dynamics soon changed with Godwin's marriage to Mary Jane Clairmont in 1801. Clairmont brought her own two children into the union, and she and Godwin later had a son together. Shelley never got along with her stepmother. Her stepmother decided that her stepsister Jane (later Claire) should be sent away to school, but she saw no need to educate Shelley. The Godwin household had a number of distinguished guests during Shelley's childhood, including Samuel Taylor Coleridge and William Wordsworth. While she didn't have a formal education, she did make great use of her father's extensive library. Shelley could often be found reading, sometimes by her mother's grave. She also liked to daydream, escaping from her often challenging home life into her imagination. Shelley also found a creative outlet in writing. According to The Life and Letters of Mary Wollstonecraft, she once explained that "As a child, I scribbled; and my favourite pastime, during the hours given me for recreation, was to 'write stories.'" She published her first poem, "Mounseer Nongtongpaw," in 1807, through her father's company.

Husband During the summer of 1812, Shelley went to Scotland to stay with an acquaintance of her father William Baxter and his family. There she experienced a type of domestic tranquility she had never known. Shelley returned to the Baxters' home the following year. In 1814, Mary began a relationship with poet Percy Bysshe Shelley. Percy Shelley was a devoted student of her father, but he soon focused his attentions on Mary. He was still married to his first wife when he and the teenaged Mary fled England together that same year. The couple was accompanied by Mary's stepsister Jane. Mary's actions alienated her from her father who did not speak to her for some time. Writing 'Frankenstein' and Other Works Mary and Percy traveled about Europe for a time. They struggled financially and faced the loss of their first child in 1815. Mary delivered a baby girl who only lived for a few days. The following summer, the Shelleys were in Switzerland with Jane Clairmont, Lord Byron and John Polidori. The group entertained themselves one rainy day by reading a book of ghost stories. Lord Byron suggested that they all should try their hand at writing their own horror story. It was at this time that Mary Shelley began work on what would become her most famous novel, Frankenstein, or the Modern Prometheus. Later that year, Mary suffered the loss of her half-sister Fanny who committed suicide. Another suicide, this time by Percy's wife, occurred a short time later. Mary and Percy Shelley were finally able to wed in December 1816. She published a travelogue of their escape to Europe, History of a Six Weeks' Tour (1817), while continuing to work on her soon-to-famous monster tale. In 1818, Frankenstein, or the Modern Prometheus debuted as a new novel from an anonymous author. Many thought that Percy Bysshe Shelley had written it since he penned its introduction. The book proved to be a huge success. That same year, the Shelleys moved to Italy. While Mary seemed devoted to her husband, she did not have the easiest marriage. Their union was riddled with adultery and heartache, including the death of two more of their children. Born in 1819, their son, Percy Florence, was the only child to live to adulthood. Mary's life was rocked by another tragedy in 1822 when her husband drowned. He had been out sailing with a friend in the Gulf of Spezia.