In 1813 Shelley self-published his first major work, the long poem Queen Mab. Set in a utopian fairyland with a protagonist named after his daughter Ianthe, the poem was an allegory for Shelley's political ideals. Shelley passionately believed that society was capable of perfecting, or at least bettering, itself. The poem employed various political theories, including atheism, the importance of revolution, and the works of William Godwin, the anarchist political philosopher whom Shelley greatly admired.
After establishing a correspondence with Godwin, Shelley began spending time in the philosopher's London home. There he met Godwin's 16-year-old daughter Mary, a young woman whose passion and intelligence equaled his own. She was the only child of the philosopher and his wife, the feminist Mary Wollstonecraft, who died giving birth to Mary. Shelley and Mary Godwin fell in love. He explained his feelings to his wife Harriet - now pregnant with their second child - believing that if she shared his ideals and truly loved him, she would want him to follow his heart. He was disappointed to learn that she did not. Nonetheless his relationship with Mary squared with his idea of honor. The truth was, he was in love with this person - if those were the facts, then how could it be wrong for them to be together?
In July 1814, Shelley, Mary Godwin and Godwin's half-sister Claire Clairmont ran off together to the Continent, where they spent six weeks gallivanting through Western Europe. When they returned to England in September, Mary Godwin was pregnant, Shelley was heavily in debt and the reputations of everyone involved were destroyed. Though he was still legally married to Harriet, he and Mary lived as husband and wife. Shelley was forced into hiding for a few months to escape his many creditors. Shortly after their return, Shelley's grandfather died and he came into his full inheritance, the only thing that spared the couple from financial disaster. Tragically the couple's first child was born prematurely and died just weeks after birth. Their second, a son named William, was born 24 January 1816.
"I never was attached to that great sect," Shelley wrote in his poem Epipsychidion, "Whose doctrine is, that each one should select/ Out of the crowd a mistress or a friend,/ And all the rest, though fair and wise, commend/ To cold oblivion, though it is in the code/ Of modern morals."10 This is Shelley's poetic way of saying that he was a believer in free love. When Shelley's best friend Thomas Hogg expressed interest in Mary, Shelley encouraged both of them to go for it. Shelley may also have had an affair with Mary's half-sister Claire Clairmont, who lived with them. Though to the rest of English society the group of young Romantics seemed immoral and scandalous, their behavior aligned with Shelley's personal, unique moral code. He and Mary were trying to change the world for the better by making it more free, true, and beautiful.
Claire Clairmont had begun a relationship with the poet Lord Byron, a dark, perverse character who avoided philosophical debates on morality by simply have no ethics whatsoever. At the urging of a pregnant Claire, she, Lord Byron, Mary Godwin and Shelley spent the summer of 1816 together in Switzerland. Shelley and Byron developed a close friendship, with both men believing that Byron was the better poet. Certainly in their lifetimes, Byron's words were better known - "Shelley could number his readers on his fingers,"11 a friend of his wrote after his death. Mary also seemed poised to eclipse his literary fame. On a rainy afternoon, at Byron's suggestion, she began a ghost story that turned into her novel, Frankenstein.
The family returned to England, only to meet tragedy. In October, Mary Godwin's troubled half-sister Fanny Godwin committed suicide. Percy and Mary were flooded with the sorrow and anguish of suicide survivors. "Her voice did quiver as we parted,/ Yet knew I not that heart was broken/ From which it came, and I departed/ Heeding not the words then spoken,"12 Shelley wrote in his poem "On Fanny Godwin." Just two months later, Harriet Shelley - pregnant with Percy's third child - threw herself in London's Serpentine River and drowned. Shelley was again overcome with grief and guilt. Compounding his pain was the fact that the courts denied him custody of his two children with Harriet, citing his unconventional and allegedly immoral lifestyle. He and Mary married on 30 December 1816. Mary Shelley gave birth to their daughter, Clara Everina, on 14 May 1817.