William Petty
William Petty (1623-1687), in his day a noted English economist, scientist, philosopher, Fellow of the Royal Society and politician. He first came to prominence serving Oliver Cromwell and the Commonwealth in Ireland and, like many others, later served under King Charles II and King James II. Knighted in 1661, he became the great-grandfather of Prime Minister William Petty Fitzmaurice, 2nd Earl of Shelburne and 1st Marquess of Lansdowne.