Northumberland is a large county of ancient origins as an independent kingdom and one of the earliest centres of British Christianity. A great border region, it is full of peel houses and castles, like Dunstanburgh, Alnwick, Prudhoe, Bamburgh, and Warkworth. The industrial development of Tyneside, largely a 19th-cent. phenomenon, is confined to the south-east corner. The rest is a shire of high fells and deep valleys, thinly populated, with small market towns like Corbridge, Haltwhistle, Morpeth, Hexham, Rothbury, Wooler, and Alnwick. Berwick-on-Tweed is part of Northumberland geographically, though a county in its own right. The southern boundary is the Tyne, the northern the Tweed.

The main northern tribe in pre-Roman times was the Brigantes, though Camden placed the county under the Ottadini or Votadini. The crossing of the Tyne at the Pons Aelium must soon have become a settlement, the nucleus of Newcastle itself. Hadrian's Wall, which runs east–west across the county, was for decades the limit of the Roman empire. In early Saxon times, the area formed part of the kingdom of Bernicia, which joined with Deira to the south in 651 to constitute Northumbria (the land north of the Humber), which for centuries disputed supremacy with Mercia and Wessex. The conversion of King Edwin in the early 7th cent. led to the foundation of a famous monastery on Lindisfarne or Holy Island, and the decision of the Synod of Whitby in 664 to follow the Roman practice of worship pulled Northumbria into a southerly orbit. In the late 8th cent. the area began to suffer from Danish raids and in the following century was in conflict with the Viking kingdom of York. In 920 it submitted to Edward, king of Wessex, at Bakewell, and subsequent attempts to recover its independence were of no avail. After the defeat at Carham in 1016 the lands north of the Tweed were ceded to the kingdom of Scotland.

Northumbrian resistance to the Normans after Hastings led to William I's despoiling of the area in 1069. It was not included in the Domesday survey, having yet to recover from the devastation. In the later Middle Ages it was the first line of defence against the Scots, the border region being divided up into marches. Vast power was wielded by the local lords, particularly the Percies of Alnwick. England's weakness under Stephen led to the Scottish king David I occupying the county and pushing his border south to the Tees. It was retaken by Henry II, though Berwick, in the far north, changed hands repeatedly. The remoter parts of the county like Redesdale, Coquetdale, and Allendale were under fitful control, border raiding was common, and bloody encounters, like Otterburn in 1388 when Percy fought Douglas, were not uncommon. Even in the reign of Elizabeth I, feudal loyalties remained strong, and more than 5,000 men turned out to support the catholic rising of the northern earls, Northumberland and Westmorland, in 1569. The union with Scotland in 1603 gave some respite from cattle-raiding. The last spasm of lawlessness was produced by the Jacobite movement. Sir John Fenwick, a former member for the county, was executed in 1697 for conspiracy against William III, and Thomas Forster, another member, was supported by a number of shire gentlemen in the '15, though they did little save proclaim the old pretender at Warkworth and occupy Holy Island for one day.

Camden, in 1586, drew a picture of a county that was still wild and untamed: ‘the county itself is mostly rough and barren, and seems to have hardened the very carcasses of its inhabitants.’ One hundred years later, things were changing. Regular services plied the Great North Road, and Edmund Gibson wrote in 1695 that strangers were no novelty to the shire, nor had cause to be apprehensive: ‘a roundlet of red wine is a greater rarity in a countryman's house in Middlesex than on the borders of Northumberland … the gentry are generally persons of address and breeding, the peasants are as knowing a people, and as courteous to strangers, as a man shall readily meet with in any other part.’

In so large a county, administration was bound to be decentralized. The assizes were held in Newcastle, but the elections for the shire at Alnwick. Quarter sessions were held at Newcastle, Alnwick, Morpeth, and Hexham in turn. But Newcastle had always been by far the most important town and in the 19th cent. it grew disproportionately to its neighbours. From a base of about 28,000 in 1801, it was 87,000 by 1851, and by 1914, having swallowed its surrounding villages, had reached 271,000. The increase was due, in the main, to coal-mining and shipbuilding. In 1857, 4 million tons of coal was being exported from the Tyne: by 1888 it had reached 10 million tons, and by 1900 17 million tons. By the 20th cent. there were far more miners in the county than farm labourers. The long-established tradition of shipbuilding was transformed after 1850. Armstrong's works at Elswick were opened in 1847, Parsons' at Heaton in 1889. The political effect of this economic development was acknowledged in 1974 with the creation of a new county of Tyne and Wear, and although the new authority was itself abolished in 1986, the areas north of the Tyne did not return to Northumberland: instead Newcastle and North Tyneside were made unitary authorities. The decision of a Roman commander to cross the Tyne at Pons Aelium had lengthy consequences.

J. A. Cannon

Northumberland County in ne England, on the border with Scotland; the county town is Morpeth. In the 2nd century ad, Hadrian's Wall was built to defend Roman Britain from the northern tribes. In the 7th century, the region became part of the Saxon Kingdom of Northumbria. The land slopes down from the Cheviot Hills in the nw, and the region is drained by the Tyne, Tweed, Blythe and Coquet rivers. The county is largely rural, the chief farming activities being cattle and sheep rearing. Barley and oats are grown and forestry is important. Coal is mined. Area: 5033sq km (1943sq mi). (1996 est.) 307,400.