Like most other counties in the south of England, Hertfordshire possesses the remains of several Norman castles, most of which appear to date back no further than the Conquest, while others, like Berkhampstead (where, as we have seen in a previous section, Mercian kings held their courts), have been supposed to be constructed on the site of earlier buildings of a similar nature.

The total number of castles built by the Normans to overawe their new English subjects is stated to have been about 1100. These, as may naturally be surmised, varied considerably in size, some being royal castles, constructed for the defence of the country generally and ruled by a constable or guardian, while others belonged to individual Norman noblemen for the defence of their own estates, and were for the most part the terror of the surrounding districts.

A Norman castle of the highest type occupied a large area, the lofty and massive outer wall enclosing a space of several acres, and being surmounted with towers and protected by bastions, while it was also surrounded by a moat or ditch. Within the enclosure thus formed were three main divisions, the first of which was the outer bailey, or courtyard, entered by a towered gateway furnished with a portcullis (that is to say, a gate which could be dropped down from, and drawn up into, the tower by means of a system of chains and pulleys) and a drawbridge. The stables and other buildings were contained in this court. Next came the inner bailey, or quadrangle, likewise entered through a towered and fortified gateway, and containing the chapel, the barracks, and the keep. Lastly, we have the keep or donjon itself, which always contained a well, and constituted the final portion which was defended during a protracted siege when the garrison was hard pressed. In choosing the site for such a military castle, either a more or less isolated and steep hill or rock might be selected, or a situation in marshy low-lands, where access might be rendered difficult or impossible by damming back the waters.

The Norman castle at Berkhampstead, which stood close to the present railway due east of the station, and portions of the ruins of which may be seen from the train, was built by Robert Earl of Morton, brother of William the Conqueror. According to a recent writer, the earthworks of this castle represent the original fortress founded by the Conqueror, and the appellation of a “burh” to the structure is consequently erroneous. A Saxon “burh” or “burg” was a fortified town, whereas the moated mound of Berkhampstead, like those at Hertford, Bishop’s Stortford, Anstey, Bennington, and Pirton, are essentially Norman castles of the type known as “mottes,” or, from their shape, as “mount and bailey castles.” It is a common idea that Berkhampstead was originally a stone castle, but the earthworks now remaining really represent the fortress itself. In the reign of Henry II the custody of Berkhampstead Castle was entrusted to Thomas À Becket, who replaced the old wooden defences (such as stockades, palisades, and towers) originally crowning the banks, by walls of flint rubble, remains of which still partly surround the enclosure.

Hertford Castle, the site of which forms the residence of His Majesty’s judges during the assizes, was built by Edward the Elder about the year 905; and after the conquest William I placed both castle and town in the custody of Peter de Valoignes. Other ancient castles and baileys in the county include the following, viz:—

Anstey Castle, situated about a mile from the eastern border of Hertfordshire, on the watershed between the Stort and the Quin. Bennington Castle, built on high ground about a mile from the river Beane and some two miles from Walkern Bury; the ruins include the remains of a small, square keep, as well as of a bailey. Waytemore Castle, Bishop’s Stortford, belonging to the Bishop of London, is an excellent example of the type of fortress which owes the main part of its strength to being situated in a practically impassable morass; that is to say, when the latter was kept well flooded. The flint rubble walls of the keep are fully a dozen feet in thickness.

Smaller baileys existed at High Down, near Pirton; at Periwinkle Hill, on nearly level ground, midway between Reed and Barkway; and also at Walkern, on the Beane, about a mile and a half distant from the village. In the last of these it is noteworthy that the church is situated close to the castle, although, unlike the one at Anstey, it does not appear to have been included in an outer ward.

The class of defensive works known as homestead moats—that is to say, simple enclosures formed into islands by means of moats containing water—do not, perhaps, strictly speaking, come under the title of either architectural or military structures. Still this seems the most convenient place in which to mention them. The northern and eastern districts of Hertfordshire are remarkable for the enormous number of these homestead moats; these districts being equalled in this respect only by Essex and Suffolk. On the western side of the county they are comparatively uncommon.

“These enclosures,” observes a writer in the Victoria History of the county, “vary greatly in size, shape, and position, and it is obvious that they do not all belong to one period, for in all ages to surround a piece of land with a ditch has been one of the most elementary forms of defence. There are, however, as with the larger earthworks, certain typical forms.... It should be noted that the typical feature of a homestead moat is that the earth, dug to form the deep surrounding ditch, was thrown on to the inclosure and spread, thus raising the island slightly above the surrounding level. The construction of moats, except for ornamental purposes, having ceased when the state of the country no longer necessitated such protective measures against men or wild beasts, they often fell into decay, or were partially filled up, and their vestiges converted into ponds, while many may have been obliterated as interfering with agriculture, but there still remain a large number.”

To reproduce the list of these would occupy far too much space; and it must suffice to mention that examples of homestead moats may be seen in the parishes of Ashwell, Braughing, Pirton, and Sawbridgeworth.

A step in advance of the homestead moat was formed by earthworks made on the same plan as the latter, but provided with a rampart and a “fosse,” or ditch, and in some cases also with outer defences. Of this type of earthwork three examples are definitely known to occur in the county, namely one at Bygrave, a second at Whomerley Wood to the south-east of Stevenage, and a third at Well Wood, Watton.

Yet another kind of defensive earthwork is to be found in the shape of walls, ramparts, or ditches surrounding the sites of ancient villages. Of this we have a local example in Kingsbury Castle, an old fortified village lying to the south-west of the city of St Albans, and covering an area of about 27½ acres. The village stood upon a hill, of which the summit has been planed off and the material employed to form steep banks or ramparts, one of which was partially thrown down to form the present Verulam Road, while another portion persists in the shape of a steep fall in the gardens or yards at the back of the houses on the north side of Fishpool Street. The main structure of the castle was demolished during the tenth century, and the remnant about the year 1152. It may be added that the clay-pits on the north side of Kingsbury Castle are the reputed source of the material of the Roman bricks of which Verulam is built.

The gigantic earthworks of the type of Beech Bottom and Grimm’s Dyke have been mentioned in an earlier section.