Avon was the name of a county in southwestern part of England that existed from 1974 to 1996.
The Saxon leader Cheldric fled through Avon after the battle of Bath.
Note
Avon is a common name for rivers in several English-speaking countries, particularly in the United Kingdom. There are multiple rivers named Avon in England, Scotland, and Wales. The word avon itself is derived from the Welsh word for river, afon.
Source
Brut | Layamon, late 12th century to mid-13th centuryv