The name of a county often gives a clue to how it was formed, either as a division that took its name from a centre of administration, an ancient kingdom, or an area occupied by an ethnic group.
 The majority of English counties are in the first category, with the name formed by combining the central town with the suffix "-shire", for example
Yorkshire. Former kingdoms, which became
earldoms in the
united England did not feature this formulation; so for Kent, the former kingdom of the
Jutes, "Kentshire" was not used. Counties ending in the suffix "-sex" are also in this category and are former Saxon kingdoms. Many of these names are formed from compass directions. The third category includes counties such as
Devon where the name corresponds to the tribes who inhabited the area.
County Durham is anomalous in terms of naming and origin, not falling into any of the three categories. Instead it was a
diocese that was turned into the
County Palatine of Durham, ruled by the
Bishop of Durham.
 The expected form would otherwise be "Durhamshire", but it was rarely used.
There are customary abbreviations for many of the counties. In most cases these consist of simple truncation, usually with an "s" at the end signifying "shire", such as "Berks" for
Berkshire or "Bucks" for
Buckinghamshire. Some abbreviations are not obvious, such as "Salop" for
Shropshire, from the
Norman-derived word for its county town Shrewsbury; "Oxon" for
Oxfordshire, from Latin Oxonium (referring to both the county and the city of Oxford); "Hants" for
Hampshire; and "Northants" for
 Counties were often prefixed with "County of" in official contexts, such as "County of Kent". Those counties named after central towns lost the -"shire" suffix, for example Yorkshire would be known as "County of York". This usage was sometimes followed even where there was no town by that name, such as the "County of Berks". The "-shire" suffix was also appended for some counties, such as "Devonshire", "Dorsetshire" and "Somersetshire", despite their origin.
 There is still a
Duke of Devonshire.