 In May 1816 , Mary Godwin , Percy Shelley , and their son travelled to Geneva with Claire Clairmont . They planned to spend the summer with the poet Lord Byron , whose recent affair with Claire had left her pregnant . The party arrived at Geneva on 14 May 1816 , where Mary called herself " Mrs Shelley " . Byron joined them on 25 May , with his young physician , John William Polidori , and rented the Villa <unk> , close to Lake Geneva at the village of <unk> ; Percy Shelley rented a smaller building called Maison Chapuis on the waterfront nearby . They spent their time writing , boating on the lake , and talking late into the night . 
