People grieve in different ways. Back in the 1600s, it wasn’t uncommon to make jewelry out of the hair of deceased loved ones. In some parts of Madagascar, people dig up their dead relatives every few years to dance with them. And even now, we consider it fairly normal to incinerate people, then save them in decorative urns on our mantels. Taking all that into account, maybe what Mary Shelley did when her husband died wasn't that weird.
Percy Bysshe Shelley was just 29 when he drowned after his boat, Don Juan, was caught in a storm on July 8, 1822. Shelley's body and those of his two sailing companions were found 10 days later, identifiable only by their clothing. Shelley had stashed a book of John Keats poems in his pocket.
The poet was cremated, but for some reason, his heart refused to burn. Modern-day physicians believe it may have calcified due to an earlier bout with tuberculosis. Though Percy’s friend, Leigh Hunt, originally claimed the heart—he was there for the funeral pyre-style cremation and felt he had a right to keep the unscathed organ—it was eventually turned over to Mary.
Instead of burying it with the rest of his remains in the Protestant Cemetery in Rome, Mary kept the heart in a silken shroud, and is said to have carried it with her nearly everywhere for years. In 1852, a year after she died, Percy’s heart was found in her desk. It was wrapped in the pages of one of his last poems, Adonais. The heart was eventually buried in the family vault with their son, Percy Florence Shelley, when he died in 1889.