Reverend William O'Neill, 1st Baron O'Neill was an Anglo-Irish hereditary peer, clergyman and musical composer.
Background
The eldest son of Reverend Edward Chichester, he was a member of the prominent Irish Chichester family headed by the Marquess of Donegall. He was the great-great-great-grandson of John Chichester, grandson of Edward Chichester, 1st Viscount Chichester, and younger brother of Arthur Chichester, 2nd Earl of Donegall.
Education
O'Neill was educated at Foyle College, Derry, Shrewsbury School and Trinity College, Dublin, and was ordained in 1837.
Career
Born William Chichester, he changed his surname to O'Neill in 1855. He was a prominent church organist and composer of church music, glees and songs. In 1855 he succeeded to the substantial O'Neill estates on the death of his relative John O'Neill, 3rd Viscount O'Neill (on whose death the viscountcy became extinct) and assumed by Royal licence the surname of O'Neill in lieu of Chichester the same year.
In 1868 the O'Neill title was revived when he was raised to the peerage as Baron O'Neill, of Shane's Castle in the County Antrim. Two of Lord O'Neill's descendants gained particular distinction. Elizabeth Grace, Lady O'Neill, died in 1905.