While most Jesus College graduates of the first 300 years became clergymen, a few took up medicine, law, or the pursuits of MPs and country gentry. During the late 1630s and early 1640s, a group of South Welsh landowners' sons at Jesus included Mansells from Margam Abbey and Stradlings from St Donat's Castle, who later fought on opposite sides in the campaigns of the Civil War, and John and James Herbert, young sons of the hereditary College Visitor, Philip, 4th Earl of Pembroke. The Metaphysical poet Henry Vaughan the Silurist (1622-1695) from Breconshire, whose twin brother Thomas was a commoner and scholar of Jesus between 1638 and 1648, was briefly a member of the College, probably in the immediately pre-Civil War period of the early 1640s.