 Sir Bevil Grenville (1596–1643) (eldest son and heir), a Royalist soldier in the Civil War, killed in action in heroic circumstances at the Battle of Lansdowne in 1643.He served as MP for Cornwall 1621–1625 and 1640–42, and for Launceston 1625–1629 and 1640.He married Grace Smith, a daughter by his second marriage of Sir George Smith (died 1619) of Madworthy, near Exeter, Devon, a merchant who served as MP for Exeter in 1604, was three times Mayor of Exeter and was Exeter's richest citizen, possessing 25 manors.