Jenkins describes Company-Sergeant Major Cadwallader as “cleanshaven, with the severely puritanical countenance of an Ironside in a Victorian illustration to a Cavalier-and-Roundhead romance.” [VB 10/6].
The English Civil Wars (1642-1651) pitted the Cavaliers (followers of King Charles I and King Charles II) against the Roundheads (Parliamentarians or followers of Oliver Cromwell). The Roundheads were named for their bowl-like haircuts; their troops were called Ironsides, because Old Ironsides was one of Cromwell’s nicknames. Many romantic novels have been written about this era. A pre-Victorian example is Sir Walter Scott’s Woodstock, or the Cavalier (1826). We have not found the illustration that Jenkins recalls, but the image at the left qualifies as Victorian (1837-1901) and shows Cromwell with a portrait of Charles I by Van Dyck. Another Victorian source of engraved illustrations is the history Great Civil War or The Times of Charles I. and Cromwell, written by Richard Cattermole and illustrated by George Cattermole.
For a Victorian image of Roundheads, we can turn to the painting above by William Frederick Yeames. The Roundhead officer seated in the center wears an orange sash, which was characteristic Ironside attire. We know that the Ironside standing to his left is a sergeant because the halberd in his left hand is a sign of rank. To imagine Cadwallader, we will just need to shave the mustache from his stern face.