Speed was everything. Brick would have taken years; the threat felt closer than that. The Corporation provided land at the tip of the headland where the Wear met the sea, exactly the spot a hostile fleet would aim for if it wanted to choke off Sunderland's coal trade. The buildings were thrown together in timber to a standard military pattern: nineteen large barrack rooms, each sleeping 36 men in double berths, 1,528 infantry in total. Twenty sergeants' rooms with bunks for four. The gun battery from the mid-18th century, already in place beyond the barracks toward the sea, was integrated into the defensive scheme. By 1803 an 80-bed hospital had been added. The French invasion never came to Sunderland - it would be Nelson, far out at sea, who would decide that question at Trafalgar in 1805 - but the barracks settled in as if they would always be needed.

In 1873 the Cardwell Reforms reorganised the British Army by county, and Sunderland Barracks became the depot for two regiments: the 68th (Durham) Regiment of Foot, raised locally, and the 106th Regiment of Foot, descended from the Bombay Light Infantry of the Honourable East India Company. The 68th had fought in the Crimea and against the Maori in New Zealand. The 106th had served across India, then transferred to the Crown in 1862. Then in 1881 the Childers Reforms merged the two into the Durham Light Infantry, and the headquarters moved away. After that the Sunderland barracks were mostly Royal Artillery, the gunners who would in the next century leave Wearside for the Western Front and South African mining camps and any number of imperial frontiers.

By the early 20th century, the buildings that had been thrown up in a panic in 1794 were tired. The timber was rotting, the ground around them had been transformed - in the 1840s Hudson Dock had been carved out of reclaimed land just east of the barracks, and by 1900 the whole headland was an industrial complex of dock basins, cranes, and rail sidings rather than the windswept moor the soldiers had marched out onto in 1794. In May 1909 the War Office formally began considering disposal of the site, and the barracks were decommissioned shortly afterward. They lingered, mostly empty, for two more decades. In the early 1930s the demolition crews finally came. Corporation Quay, the new dock and warehousing facility Sunderland needed for its mid-century shipping, rose where the barracks had been. No part of them now stands.

When the barracks were new, the High Street ran almost exactly a mile between them at the east end and Bishopwearmouth Church - now Sunderland Minster - at the west. That mile was the spine of late Georgian Sunderland: shops, public houses, the homes of merchants who had grown rich on coal, and the constant traffic of soldiers walking from their barracks into town and back. They left no monument. The men of the 68th and the 106th are remembered at the Durham Light Infantry Museum near Durham Cathedral, and the lifeboat crews their gun battery once protected still launch from a marina a few hundred metres north of where Sunderland Barracks stood. If you stand on the quayside today and look east toward the river mouth, the wind comes in the same direction. The watch they kept is part of the geography even when the buildings are not.