In February 1815, Mary gave birth to a daughter, who was born prematurely and who subsequently died in March of the same year. The couple settled in Bishopgate, England and a second child, William, was born.
In the summer of 1816, a tour of continental Europe was proposed. At a stop in Switzerland, the couple and Mary's stepsister, Claire, rented a house near another British writer, Lord Byron. The summer proved wet and unseasonable; Byron suggested the group take to writing ghost stories to pass the time. It was during this summer that the form for Frankenstein was to take shape. The story was first only a few pages, but with the encouragement of Percy, the tale took on a greater length. Mary's story, the best of the group, was so frightening to Byron that he ran "shrieking in horror" from the room. Frankenstein was published in 1818.
In November 1816, Fanny, Mary's half-sister, committed suicide. A few weeks later, in December 1816, Shelley's first wife Harriet also killed herself. Within two weeks, Percy and Mary were married in St. Mildred's Church in London on December 30, 1816. Early the next year, the couple moved to Marlow, England and a third child, Clara Everina, was born. In 1818, the Shelley's left England for Italy to escape mounting debt and to improve Percy's health. It was during this time that both small children died; Clara died in September 1818, and William died the following June, in 1819. Mary was miserable and disconsolate at 21 and 22 years of age. She did recover somewhat later in November 1819 when her son Percy was born in Florence, Italy. He would become the only Shelley child to survive to adulthood. Mary did not remain idle as a writer during this time, as she began a new novel, Valperga.
