Cooper's Map of Hertfordshire, 1808

In Saxon times the country was divided into administrative units called "Hundreds" and these were still used for various purposes until comparatively recent times. Most recently the very important Victoria County History of Hertfordshire (which is available in most large libraries) divides the country up into its old hundreds. The hundreds were called Braughing, Broadwater, Cashio, Dacorum, Edwinstree, Hertford, Hitchin and Odsey