c.5000 - Neolithic (new stone age) Period begins; first evidence of farming appears; stone axes, antler combs, pottery in common use.
c.4000 - Construction of the "Sweet Track" (named for its discoverer, Ray Sweet) begun; many similar raised, wooden walkways were constructed at this time providing a way to traverse the low, boggy, swampy areas in the Somerset Levels, near Glastonbury; earliest-known camps or communities appear (ie. Hembury, Devon).
c.3500-3000 - First appearance of long barrows and chambered tombs; at Hambledon Hill (Dorset), the primitive burial rite known as "corpse exposure" was practiced, wherein bodies were left in the open air to decompose or be consumed by animals and birds.
c.3000-2500 - Castlerigg Stone Circle (Cumbria), one of Britain's earliest and most beautiful, begun; Pentre Ifan (Dyfed), a classic example of a chambered tomb, constructed; Bryn Celli Ddu (Anglesey), known as the "mound in the dark grove," begun, one of the finest examples of a "passage grave."
c.2500 - Bronze Age begins; multi-chambered tombs in use (ie. West Kennet Long Barrow) first appearance of henge "monuments;" construction begun on Silbury Hill, Europe's largest prehistoric, man-made hill (132 ft); "Beaker Folk," identified by the pottery beakers (along with other objects) found in their single burial sites.
c.2500-1500 - Most stone circles in British Isles erected during this period; pupose of the circles is uncertain, although most experts speculate that they had either astronomical or ritual uses.
c.2300 - Construction begun on Britain's largest stone circle at Avebury.
c.2000 - Metal objects are widely manufactured in England about this time, first from copper, then with arsenic and tin added; woven cloth appears in Britain, evidenced by findings of pins and cloth fasteners in graves; construction begun on Stonehenge's inner ring of bluestones.
c.1800-1200 - Secular control of society passes from priests to those who control the manufacture of metal objects.
c.1500 - Farms (houses and separate, walled fields) in use on Dartmoor (Devon) and in uplands of Wales; stone circles seem to fall into disuse and decay around this time, perhaps due to a re-orientation of the society's religious attitudes and practices; burial mounds cease to be constructed; burials made near stone circles or in flat cemetaries.
c.1200-1000 - Emergence of a warrior class who now begins to take a central role in society. Some believe that these people, also known as the Urnfield civilization, are the "proto-Celts."
c.1100 - Geoffrey of Monmouth suggests that Brutus arrives about this time.
c.1000 - Earliest hill-top earthworks ("hillforts") begin to appear, also fortified farmsteads; increasing sophistication of arts and crafts, particularly in decorative personal and animal ornamentation.
c.600 - Iron replaces bronze, Iron Age begins; construction of Old Sarum begun.
c.500 - Evidence of the spread of Celtic customs and artefacts across Britain; more and varied types of pottery in use, more characteristic decoration of jewelry. There was no known invasion of Britain by the Celts; they probably gradually infiltrated into British society through trade and other contact over a period of several hundred years; Druids, the intellectual class of the Celts (their own word for themselves, meaning "the hidden people"), begin a thousand year floruit.
c.150 - Metal coinage comes into use; widespread contact with continent.
c.100 - Flourishing of Carn Euny (Cornwall), an iron age village with interlocking stone court-yard houses; community features a "fogou," an underground chamber used, possibly, for storage or defense.