Worcester, Edward Somerset, 6th earl and 2d marquess of

Worcester, Edward Somerset, 6th earl and 2d marquess of (ws`tər), 1601?–1667, English soldier and inventor. Known as Lord Herbert after 1628, he received the title earl of Glamorgan in 1644 and succeeded as earl and marquess of Worcester in 1646. Sent to raise royalist troops in Ireland, Glamorgan, himself a Roman Catholic, exceeded his instructions when he signed (1645) on behalf of Charles I a treaty with the Irish Roman Catholics that would have given them freedom of worship. This treaty proved so offensive to the Protestant royalists that Charles repudiated it. Worcester went to France in 1648 and was imprisoned for two years on his return to England (1652). Most of his estates were returned to him at the Restoration (1660). He was interested in mechanical experiments, which he described in a long treatise, and is said to have invented a steam engine.