Cumberland consisted of the western part of the Lake District, a surrounding coastal plain, narrow towards the south, broadening towards the north, and two outlying areas, a hilly district to the east towards Alston, and fertile lands north of Hadrian's Wall towards the Scottish border. The northern part is drained by the Eden, running through Carlisle, and its tributaries the Caldew and the Petteril, running north from Penrith; the Derwent flows from Derwentwater and Bassenthwaite through Cockermouth to Workington; and the southern parts are drained by the Duddon. The great slab of hills in the east is drained by the south Tyne and the Tees, the water finishing in the North Sea. The boundary with Scotland was the river Liddel; with Westmorland the Eamont, flowing out of Ullswater; and with Lancashire, the Duddon. Carlisle grew as a bridge over the Eden, where an important east–west route from Newcastle towards Ireland intersected with two major north–south routes, an ancient road through Tebay, and an old route from Yorkshire across Stainmore via Scotch Corner, Brough, and Appleby.

Cumberland was one of the last shires to take shape and for centuries was disputed between England and Scotland. In Caesar's time it was in the territory of the Brigantes, but that was a loose confederation and the local tribe were the Carvetii, inhabiting the Solway region. The Romans were interested in the area for strategic and economic reasons. In the end, their boundary with the Scots settled along the line of Hadrian's Wall, which entered Cumbria at Gilsland and ran to Bowes-on-Solway. Carlisle (Luguvalium) was a major Roman town, protected by a fort at Stanwix, and there were important forts at Hardknott (the worst posting in Roman Britain), and at Maryport, Penrith, Netherby, and Bewcastle. Ravenglass, where the Mite, Irt, and Esk meet, was a superb natural harbour until it silted up. The local mineral resources were also exploited—silver and lead from the Alston region, copper, coal, and iron elsewhere. After the Roman period, the orientation of the region was towards Scotland and Ireland rather than the south. It was a meeting-place of peoples and cultures. The basic stratum was Welsh or British, and the name, Cumberland, means the land of the Cumbri—the Welsh. But the Saxons penetrated across from Yorkshire and from Northumbria and later there were settlers from Ireland and the Isle of Man, who left Norse place-names—Aspatria, Cleator, Ennerdale, and Borrowdale. Carlisle is a case in point, since the Latinized form Luguvalium commemorates a Celtic god; Bede tells us that the Saxons called it Luel; later came the Celtic prefix caer, a city; and the Normans added a silent s making Carlisle. Roman and Celtic Christianity competed here. St Ninian's mission at Whithorn was only the other side of Solway Firth and St Kentigern certainly evangelized in the 6th cent. from Strathclyde, judging by the number of churches dedicated to him. After Æthelfryth's victory at Degsastan in 603, the region fell under Saxon rule and became part of Northumbria. The Synod of Whitby in 664 decided in favour of Roman Christianity and in 685 Ecgfrith gave Carlisle and district to St Cuthbert as part of the endowment for the diocese of Lindisfarne. Bede records how St Herbert left his island in the middle of Derwentwater to meet Cuthbert. Bewcastle cross also testifies to Northumbrian influence since it commemorates Aldfrith, who ruled 686–705.

But it was hard for any power to keep a firm grip on the area and as Northumbrian influence waned, that of Wessex rose. In 926 Athelstan, king of Wessex, met the kings of Strathclyde and Scotland at Eamont bridge to dictate terms, and reasserted his authority in 937 with a crushing victory at Brunanburh. But Wessex control of so distant a territory can only have been fitful and the fact that Athelstan's successor Edmund ravaged the region in 945 suggests that Dunmail of Strathclyde had regained it. He is probably commemorated in Dunmail raise between Windermere and Keswick. Edmund is said to have ceded the region to Malcolm, king of the Scots, though both the nature of the contract and the extent of the region remain obscure. The arrangement does not seem to have lasted long for in 1000 Æthelred was once more harrying the region, suggesting that he had lost control, probably to the Norse, since his fleet also attacked the Isle of Man.

By this time the term Cumbria was coming into use. The Normans did not at first occupy the area and neither Cumberland nor Westmorland was included in the Domesday survey in 1086. But in 1092 William Rufus brought a large force there and began building the castle at Carlisle. In 1133 Henry I established Carlisle as a bishopric. The territory was still regarded as the district of Carlisle rather than as a shire and the Scots had by no means abandoned their claims. David I of Scotland took advantage of the confusion of Stephen's reign to occupy the area and died at Carlisle in 1153. Henry II reconquered it in 1157 and though William the Lion and Alexander II of Scotland made efforts to recapture it, it stayed part of England. Westmorland was hived off to form a separate county and Alston in the east added to Cumberland, though it remained in the diocese of Durham. By the end of the 13th cent. Cumberland, like the other counties, sent two knights of the shire to Parliament.

Though Cumberland was now firmly attached to England, it remained a border county, liable to incursions great and small. The tide of war rolled backwards and forwards. The Scots besieged Carlisle in 1296; Robert I Bruce did homage in the cathedral in 1297; and Edward I died at Burgh campaigning against the Scots in 1307. The region was repeatedly ravaged in the 14th cent. During the Civil War, in 1644–5, Carlisle stood a siege from the Scots who destroyed much of the cathedral. The last serious fighting on English soil occurred in the county during Prince Charles Stuart's retreat in 1745, when he left a forlorn hope in Carlisle castle. Even in times of peace, the many peel towers were invaluable refuges against reivers and raiders.

Although not a large town, Carlisle dominated the county. Penrith had military importance because of the junction of two major routes, and the market towns of Brampton, Wigton, Cockermouth, and Keswick had local significance. Travellers avoided the area if they could. Celia Fiennes in 1698 described ‘villages of sad little huts … I took them at first sight for barns to fodder cattle in.’ But the character of the county began to change with the industrial revolution, which created an urban fringe to west Cumberland, and the revolution in taste, which brought visitors in search of Romantic scenery of lakes and hills. Local landowners were vigorous in exploiting mineral resources and opening up ports. The Lowthers sponsored Whitehaven, which exported coal to Dublin, the Curwens did the same for Workington. Copper and iron were also mined on an increasing scale. The chief beneficiary or victim of Romanticism was perhaps Keswick, on the shore of Derwentwater, which changed from a small market town into a fashionable Victorian resort and thence into a tourist trap.

By the local government reorganization of 1972 Cumberland was united with Westmorland and the Furness district of Lancashire to form Cumbria. The M6 tears through the county, through Ingelwood Forest—the forest of the English settlers—and at Sellafield on the coast the lights of a nuclear power station twinkle.

J. A. Cannon