Narcissus Marsh, English clergyman who is successively Church of Ireland Bishop of Ferns and Leighlin, Archbishop of Cashel, Archbishop of Dublin and Archbishop of Armagh, is born on December 20, 1638, at Hannington, Wiltshire.

Marsh is educated at Magdalen Hall, Hertford College, Oxford. He later becomes a fellow of Exeter College, Oxford, in 1658. In 1662 he is ordained, and presented to the living of Swindon, which he resigns in the following year.

After acting as chaplain to Seth Ward, Bishop of Exeter and then Bishop of Salisbury, and Lord Chancellor Clarendon, he is elected principal of St. Alban Hall, Oxford, in 1673. In 1679 he is appointed provost of Trinity College, Dublin, where he does much to encourage the study of the Irish language. He helps to found the Dublin Philosophical Society and contributes to it a paper entitled Introductory Essay to the Doctrine of Sounds (printed in Philosophical Transactions, No. 156, Oxford, 1684).

In 1683 Marsh is consecrated Bishop of Ferns and Leighlin, but after the accession of James II he is compelled by the turbulent soldiery to flee to England in 1689, when he becomes Vicar of Gresford, Flintshire, and Canon of St. Asaph. Returning to Ireland in 1691 after the Battle of the Boyne, he is made Archbishop of Cashel, and three years later he becomes Archbishop of Dublin. About this time, he founds Marsh’s Library in Dublin, which is the oldest public library in Ireland. He becomes Archbishop of Armagh in 1703. Between 1699 and 1711 he is six times a Lord Justice of Ireland.

Narcissus Marsh dies on November 2, 1713. His funeral oration is pronounced by his successor at Dublin, Archbishop William King. A more acerbic account is provided by Jonathan Swift.

Many oriental manuscripts belonging to Narcissus Marsh are now in the Bodleian Library in Oxford.