From Wikipedia’s “Dante Gabriel Rossetti“:
[Dante Gabriel Rossetti’s wife Elizabeth Siddal] had taken an overdose of laudanum shortly after giving birth to a dead child. Rossetti became increasingly depressed, and buried the bulk of his unpublished poems in her grave at Highgate Cemetery. … During these years, Rossetti was prevailed upon by friends to exhume his poems from his wife’s grave. This he did, collating and publishing them in 1871.