Beilby Porteus (or Porteous) was born on May 8, 1731, in York, Yorkshire, England.

He was a Bishop of Chester and London, a Church of England reformer, a leading abolitionist in England, and a writer. Educated at York and Ripon Grammar School, he was a classics scholar at Christ's College, Cambridge, becoming a fellow in 1752. In 1759, he won the Seatonian Prize for his poem “Death: A Poetical Essay,” a work for which he is still remembered. He was ordained as a priest in 1757. In 1762, he was appointed as domestic chaplain to Thomas Secker, Archbishop of Canterbury, acting as his personal assistant at Lambeth Palace for six years. During this time, he became more aware of the conditions of the enslaved Africans in the American colonies and the British West Indies. From 1769 he was chaplain to the king George III. In 1777, Porteus became a Bishop of Chester. The appalling poverty and deprivation amongst the immigrant workers in new manufacturing industries represented a huge challenge to the church. He continued to take a deep interest in the plight of West Indian slaves, preaching and campaigning actively against the slave trade. He participated in many debates in the House of Lords, becoming known as a noted abolitionist. In 1787, Porteus was appointed a Bishop of London, a position he held until his death. He was also appointed to the Privy Council and a Dean of the Chapel Royal. He supported Sir William Dolben's Slave Trade Bill and helped secure the eventual passage of the Slave Trade Act in 1807. His library, including an extensive collection of anti-slavery literature, is preserved at the University of London Library.

He was married to Margaret Hodgson. He died on May 13, 1809, in London, England.