A map of Hertfordshire, with inset maps of Hertford and the Roman settlement of Verolanium, now St Albans. The text underneath refers to Cassivellaunus, an Ancient British king who was popularly supposed to have used Verolanium as a stronghold, and his defeat by Julius Caesar.

John Speed (1552-1629) was the outstanding cartographer of his age. His 'Theatre of Great Britain' was the first atlas of the British Isles: Speed prepared the maps himself about two years before they were published. His maps and books dominated the seventeenth-century English market. The present map is taken from the 1627 English edition published by George Humble.