Valentine Greatrakes was born on 14 February 1628 at the family home at Norrisland, New Affane. His parents were William Greatrakes and Mary Harris, daughter of Sir Edward Harris, 2nd Justice of the Kings Bench in Ireland and Chief Justice of Munster. After the Munster Plantation Valentine's grandfather had settled in Co. Waterford from Derbyshire. At the outbreak of the Munster Rebellion in 1641, his mother decided to move the family to England to live with her brother Edward in Devon. In 1647 Valentine returned to Ireland. He lived at Cappoquin Castle for a year in 'contemplation'. In 1649 he became lieutenant in the Cromwellian army in the Earl of Orrery's regiment.

On leaving the army in 1654 he returned to the family home. He was appointed Clerk of the Peace for Co. Cork and Register of Transplantation. In 1661 he was involved in a noted witchcraft trial in Youghal Co. Cork. He believed he could cure people of illnesses and diseases. His first patient was a young boy, William Maher of Salterbridge, Cappoquin who suffered from Scrofula. His fame as a healer spread quickly and he was inundated with people visiting his home. He was forced to move to Youghal. Greatrakes was popularly known as 'The Stroker' because of his method of stroking his patients with his hands. He was invited to England to practice his cures. He attracted huge crowds in London and Robert Boyle witnessed many of his healing sessions.

In 1666 Greatrakes published an account of his life and cures. His funeral entry at the Herald's Office, Dublin recorded that he died on 28 November 1682 at Affane, Co. Waterford and was buried in Lismore Church. However, the Rev. Samuel Hayman writing in the 1860's stated that he is buried in the aisle of the old Affane Church next to his father.