Mary Shelley was born in 1797 to influential philosopher William Godwin and feminist Mary Wollstonecraft. She fell in love with poet Percy Shelley, though they could not initially marry as he was still wed. In 1816 at age 19, while on vacation with Lord Byron in Switzerland, Mary had a nightmare that inspired her to write her classic Gothic novel Frankenstein. Published in 1818, Frankenstein was an immediate bestseller. After Percy's death, Mary supported herself through additional writing, though none were as impactful as her first work. She died in 1851 as an established author.