The western boundary with Cornwall was set at the River Tamar by King Æthelstan in 936.
Devon was constituted as a shire of the Kingdom of England thereafter.
However, there are references to "Defenascire" in Anglo-Saxon texts from before 1000 AD (this would mean "Shire of the Devonians"), Kents Cavern in Torquay had produced human remains from 30–40,000 years ago.
Dartmoor is thought to have been occupied by Mesolithic hunter-gatherer peoples from about 6000 BC.
The arrival of William of Orange to launch the Glorious Revolution of 1688 took place at Brixham.
Devon has produced tin, copper and other metals from ancient times.
In the Brittonic, Devon is known as Welsh: , each meaning "deep valleys." (For an account of Celtic Dumnonia, see the separate article.) William Camden, in his 1607 edition of Britannia, described Devon as being one part of an older, wider country that once included Cornwall: THAT region which, according to the Geographers, is the first of all Britaine, and, growing straiter still and narrower, shooteth out farthest into the West, [...] was in antient time inhabited by those Britans whom Solinus called Dumnonii, Ptolomee Damnonii [...] For their habitation all over this Countrey is somewhat low and in valleys, which manner of dwelling is called in the British tongue Dan-munith, in which sense also the Province next adjoyning in like respect is at this day named by the Britans Duffneit, that is to say, Low valleys.
[...] But the Country of this nation is at this day divided into two parts, knowen by later names of Cornwall and Denshire, [...] The term "Devon" is normally used for everyday purposes e.g.
As well as agriculture, much of the economy of Devon is linked with tourism.
Dartmoor is the largest open space in southern England at 954 km its moorland extending across a large expanse of granite bedrock.
To the north of Dartmoor are the Culm Measures and Exmoor.
The Romans held the area under military occupation for around 350 years.
Later, the area began to experience Saxon incursions from the east around 600 AD, firstly as small bands of settlers along the coasts of Lyme Bay and southern estuaries and later as more organised bands pushing in from the east.