Denbigh Hall Bridge carrying the London and Birmingham Railway at Bletchley, Buckinghamshire: soldiers on horseback ride under the bridge as a train passes overhead. Engraving by W. Radclyffe, 1839, after G. Dodgson.

The mounted detachment depicted is from the Buckingham Yeoman Cavalry that evolved to become the Royal Buckinghamshire Hussars. Formed in 1794 at the time of the Revolutionary and Napoleonic Wars, its colonel was Richard, 2nd Duke of Buckingham and Chandos (1797-1861) who provided the ornate uniforms based on those of a 15th-century Hungarian cavalry design. The riderless white horse, saddled but with reversed boots in the stirrups and attended by a groom in undress uniform, may reflect the death of the 1st Duke in January 1839. The Duke owned Stowe House and Gardens where George Dodgson and friends sketched in 1838 (information from Hugh Dodgson, January 2020). The road is the Holyhead Road (Watling Street, later numbered A5)