Percy Bysshe Shelley died on July 8th, 1822 at the age of 29. He died off the coast of the Gulf of Spezia, which is on the north-western coast of Italy and in the northern part of the Tyrrhenian Sea. His boat was overturned during a storm that is described as happening suddenly. Shelley and his wife, Mary Shelley, had a house on this Ligurian coast, and Percy was inspired by the views and began a poem called "The Triumph of Life" -- a bit ironic, isn't it? It seems that although Percy enjoyed the location at first, Mary did not enjoy it, and suffered a miscarriage that caused both of the parents some strife. Percy apparently was struggling and was seeing apparitions and having what could be described as hallucinations. He also attempted to get prussic acid -- enough for a lethal dose, but it is unclear if he meant to kill himself. He sailed down the coast on July 1st, and on July 8th made plans to return home -- still choosing to travel despite knowing the weather was not going to be good. Their boat was spotted during a storm flying too much sail -- the sailors who found them offered to help and advised them to lower sails, but Shelley refused. Their bodies were found days later -- Shelleys' hands and face had been decomposed. His body was buried and then later dug up to be burned on a pyre -- his heart "refused to burn" and Mary Shelley kept it until her death, wrapped in a cloth. 

Information found from Wordsworth Grasmere - https://wordsworth.org.uk/blog/2014/07/08/full-fathom-five-the-poet-lies...