Hexham began as a monastery. Saint Wilfrid, Bishop of York, founded a Benedictine abbey here in 674, building it largely from stones salvaged from Hadrian's Wall a few miles north and from the Roman town at Corbridge. The Saxon crypt he built still survives below the present abbey. The town that grew up around the monastery took its name from the Old English Hagustaldes ham, the home of a hagustald (a younger son who farms outside the main settlement), or possibly from Hextildesham, after Hextilda of Tynedale (1122 to 1182), a Scottish noblewoman who granted substantial lands to the monks. The Anglo-Saxon Chronicle records that King Ælfwald of Northumbria was murdered nearby in 788 and buried in Hexham church, with 'a heavenly light' often seen on the spot where he fell.

Sitting near the Anglo-Scottish border, Hexham could not escape the border wars. William Wallace torched the town in 1297 during the First War of Scottish Independence. Fifteen years later, Robert the Bruce arrived demanding tribute, and the monks paid £2,000 to spare themselves a second burning. In 1346 King David II of Scotland led an invasion south and the monastery was sacked anyway. In 1464, during the Wars of the Roses, the Battle of Hexham was fought somewhere just south of town; the exact location is still disputed. The defeated Lancastrian commander, Henry Beaufort, 3rd Duke of Somerset, was beheaded in Hexham marketplace. Legend places Queen Margaret of Anjou in hiding afterward at a place called The Queen's Cave southwest of town, accosted by a robber. The story is good enough to have inspired an 18th-century play by George Colman the Younger, but Margaret had actually fled to France well before the battle.

On 9 March 1761, a crowd gathered in Hexham marketplace to protest changes to the militia laws, which were forcing poorer families to send sons to fight. Troops of the North York Militia, ordered to disperse them, opened fire. Around 45 people were killed. The regiment afterward bore the nickname The Hexham Butchers, an indictment that travelled north with them. The dead lie in Hexham, the soldiers responsible long since gone home, and the gaol behind the Moot Hall still stands, having held the wounded and the arrested through the days that followed.

Hexham's market square is one of the most architecturally dense town centres in northern England. The Abbey dominates the west end, the Moot Hall (a medieval gatehouse-courthouse, Grade I listed) anchors the east, and the Shambles, a covered market built by Sir Walter Blackett in 1766, occupies the middle. Behind the Moot Hall stands the Old Gaol (completed 1332, Grade I, generally considered the earliest purpose-built prison in England). The Queen's Hall, completed in 1866, holds the town library and the Brough Local Studies Collection, the second largest local history archive in Northumberland. The Austrian firm Egger runs a chipboard mill on the edge of town whose steam plume is visible for miles. Hexham Racecourse stages National Hunt steeplechases on Yarridge Heights. The Hexham Courant has covered the valley since 1864. Country Life named Hexham England's Favourite Market Town in 2005.

Coordinates 54.967 N, 2.100 W, geohash gcy88. Cruise at 2,500 to 4,000 ft AGL for a wide read of the South Tyne valley. The town sits on the south bank of the Tyne, with the wooded slope of Tyne Green descending to the river. From the air, the Abbey is unmistakable: a massive cruciform church with a square central tower at the western edge of an open market square. The A69 dual carriageway runs east-west along the north bank of the river; the A695 follows the south bank. Hexham railway station and the Egger plume sit on the north side of the river. Hadrian's Wall traces an east-west line about 4 miles north, often visible as a stone-coloured thread across rolling pasture. Newcastle International Airport (EGNT) is 19 miles east-northeast, the closest IFR field. The Pennines roll westward; the Cheviots rise to the north.