who were mary shelley's parents?
Mary Wollstonecraft William Godwin
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 In 1816 , the couple famously spent a summer with Lord Byron , John William Polidori , and Claire Clairmont near Geneva , Switzerland , where Mary conceived the idea for her novel Frankenstein . The Shelleys left Britain in 1818 for Italy , where their second and third children died before Mary Shelley gave birth to her last and only surviving child , Percy Florence Shelley . In 1822 , her husband drowned when his sailing boat sank during a storm near Viareggio . A year later , Mary Shelley returned to England and from then on devoted herself to the upbringing of her son and a career as a professional author . The last decade of her life was dogged by illness , probably caused by the brain tumour that was to kill her at the age of 53 . 

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 In 1814 , Mary began a romance with one of her father 's political followers , the then married Percy Bysshe Shelley . Together with Mary 's stepsister Claire Clairmont , Mary and Shelley left for France and traveled through Europe . Upon their return to England , Mary was pregnant with Percy 's child . Over the next two years , she and Percy faced ostracism , constant debt , and the death of their prematurely born daughter . They married in late 1816 , after the suicide of Percy Shelley 's first wife , Harriet . 

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 For a time , Mary Shelley found comfort only in her writing . The birth of her fourth child , Percy Florence , on 12 November 1819 , finally lifted her spirits , though she nursed the memory of her lost children till the end of her life . 

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 In 1814 , the seventeen @-@ year @-@ old Mary Shelley ( Mary Godwin , at the time ) ran off with Percy Bysshe Shelley to continental Europe , accompanied by Claire Clairmont , Mary 's stepsister . After six weeks of travelling , they returned to England but continued to live together . Mary returned pregnant with Percy 's child , but their infant daughter died soon after her premature birth . Percy was alienated from his family and received little financial support from them ; he was therefore harassed by creditors . In 1816 , Mary and Percy had a second child , William . The same year , Claire Clairmont began an affair with the poet Lord Byron , and in January 1817 she had a daughter by him , Allegra . The group spent the summer of 1817 with Byron at Lake Geneva , where Mary Shelley wrote Frankenstein . That fall , Percy 's wife , Harriet , committed suicide , and in December Percy and Mary were married . In September 1817 , Mary and Percy had another child , Clara . 

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 On their return to England in September , Mary and Percy moved — with Claire Clairmont , who took lodgings nearby — to Bath , where they hoped to keep Claire ’ s pregnancy secret . At Cologny , Mary Godwin had received two letters from her half @-@ sister , Fanny Imlay , who alluded to her " unhappy life " ; on 9 October , Fanny wrote an " alarming letter " from Bristol that sent Percy Shelley racing off to search for her , without success . On the morning of 10 October , Fanny Imlay was found dead in a room at a Swansea inn , along with a suicide note and a laudanum bottle . On 10 December , Percy Shelley 's wife , Harriet , was discovered drowned in the Serpentine , a lake in Hyde Park , London . Both suicides were hushed up . Harriet ’ s family obstructed Percy Shelley 's efforts — fully supported by Mary Godwin — to assume custody of his two children by Harriet . His lawyers advised him to improve his case by marrying ; so he and Mary , who was pregnant again , married on 30 December 1816 at St Mildred 's Church , Bread Street , London . Mr and Mrs Godwin were present and the marriage ended the family rift . 
