Modern Cassiobury is the area at the northern end of Watford High Street. Its name is derived from the ancient names for the land and the people who once lived there. However its exact location, in ancient times is unclear. A Roman trackway is thought to have passed through it.
The Cassi were a tribe existing at the same time as the Iceni (Boudicia's tribe) who lived in what is now known as Buckinghamshire, Bedfordshire and Hertfordshire.
Quotation from Wikepedia Cassiobury Park page:
" Caesegsho and cashio are earlier names for the area or for the hamlet that existed in the area.
The name "Caegesho" referred to a larger area of land granted by Offa to the Abbey of St Albans in 793. "Caeg" (Old English cæg) may have been a man's name, while Old English ho means "a spur of land" (see Hoo). It was spelled "Caissou" or "Chaissou" in the 11th century and gradually evolved into "Cassio". The suffix "-bury" occurs in many English place names. It comes from the Old English word for a fortified place, burh, whose dative, byrig, means "by the fort", or "by the manor". “
Cassio in many people’s minds is Cassiobury, but Cassio (with its several old spellings) is the root of the names of both a much larger area, Cashio Hundred (called Albanstow in the Domesday book), and a manor called Cassio within it.
“from A Mapp of Hartfordshire, by Richard Blome, 1673”
Using the zoom facilities of your browser will enable you to see the locations of the 8 manors within Albanstow (later called Cashio number 7 is the manor of Cassio.
1 St. Paul's Walden
3 St. Albans
4 Hanstead (House)
The map above and the photo of the page below are from the Phillmore Domesday Book ((Hertfordshire) 1976; ISBN 0 85033 137 4)
Its map of Hertfordshire (drawn by Jim Hardy) shows the 1086 boundaries of the hundreds where Cashio Hundred is identified with a capital C.
The Abbot holds RICKMANSWORTH himself. It answers for 15 hides. Land for 20 ploughs. In lordship 5 hides; 3 ploughs there; a further 2 possible.
4 Frenchmen and 22 villagers with 9 smallholders have 14 ploughs; a further 1 possible. 5 cottagers; 5 slaves. 1 mill at 5s 4d; meadow for 4 ploughs; from fish, 4s; pasture for the livestock; woodland, 1200 pigs
Total value £20 10s; when acquired £12; before 1066 £20. St. Albans held and holds this, manor in lordship.
The Abbot holds Cassio himself. It answers for 20 hides. Abbot holds 19 of them. Land for 22 ploughs. In lordship 6 hides; 5 ploughs there; a sixth possible.
3 Frenchmen and 36 villagers with 8 smallholders have 15 ploughs; a further 1 possible. A further 3 smallholders; 2 slaves. 4 mills at 26s 8d; meadow for 22 ploughs; pasture for the livestock; woodland, 1000 pigs.
Total value £28; when acquired £24; before 1066 £30. St. Albans held and holds this manor in lordship.
in ALDENHAM Geoffrey of Bec holds 1 hide under the Abbot, Land for 1 plough, but the plough is missing.
2 cottagers. woodland, 100 pigs.
The value is and was 12s; before 1066, 20s.
Black, St. Albans’ man, held this land; he could not sell.
Text from the Domesday Book for Cassio Manor
The 11th century Latin and translated texts for Cassio manor from the Phillmore Domesday Book (Hertfordshire). While the units of measurement are archaic and open to interpretation they can be usefully translated. For example:-