In 1086 - or already well before in 1066 - Turstin FitzRolf held North Cadbury, known simply as Cadbury (Cadeberie), as part of the extensive fiefdom (landed properties or estates) from King William I. under the feudal tenure per baroniam - as a feudal Baron. These land holdings were presumably all royal grants for loyal service.
William the Conqueror granted most lordships in 1066. The exact date of creation of the barony cannot be determined, as the founding charter has been lost, but was first recorded in Domesday Book of 1086. The King rewarded his loyal knights with massive amounts of land throughout the length and breadth of the country and they became ennobled and created baron. For his loyalty, William gave Turstin FitzRolf in total 77 manors. Turstin's barony comprised more than 30 manors and knights' fees in Somerset and nearby counties.
In particular Turstin held also the castle of Caerleon, at the southern end of the English frontier with unconquered Wales. Turstin's caput or seat of the barony was (North) Cadbury, but it is believed that his central area of operation seems to have been around Caerleon Castle on the English border with Glamorgan, South Wales.
Caerleon Castle was a motte-and-bailey castle. From the apparent banishment of Turstin by William II, it was held from 1088 by Wynebald de Ballon, brother of Hamelin de Ballon who held Abergavenny further up the River Usk.

After battles between the Welsh and Normans in 1171 the town was destroyed and the castle burned off. At that time Caerleon was an important market and port and became a borough probably by 1171. In 1217 the castle and borough were seized by William Marshal, 1st Earl of Pembroke and Caerleon Castle was rebuilt in stone.

These incorporated following possessions of manors or estates in several other counties adjacent to Somerset:

Gloucestershire/Worcestershire/Herefordshire
Berkshire/Wiltshire
Buckinghamshire
Devon/Dorset
Hampshire

It contained following hamlets:

1. Galhampton on the north,
2. Brookhampton, a continuation of North Cadbury,
3. Catsash, on the west and
4. Woolston, on the east.

with the famous Cadbury Castle, from which the barony takes its name. The location of the hill fort of Cadbury Castle, also known as the legendary King Arthur's Camelot.

Horsington
(anciently Horstentone)

It contained following hamlets:

1. Horsington-March on the east,
2. South Cheriton, commonly called Cheriton, on the north,
3. Wilkenthorp on the west and
4. Horwood, detached, on the east.

 Dyrham  

Dyrham Park & Church 1936

St Peter's Church Dyrham & Dyrham Park on the right

 Aust

Manor of Hasfield

Hasfield Court, Gloucestershire c.1925

St. Mary's Church, Hasfield 1912

Manor of Eastington

The Manors of Eastington and Fretherne, the two Knight's fees. Wynebald de Ballon with his son Roger donated the tithes to Bermondsey Priory.

Little Kimble

c.1920's

Hardwick with Weedon: Hardwick Manor

Hardwick Manor c.1920

A fee of Wynebald de Ballon and Henry de Newmarch. Wynebald de Ballon donated a part of Hardwick to Bermondsey Priory.