Nuln is the great industrial city of the southern Empire, straddling the River Reik where it meets the Aver, and the undisputed capital of Imperial gunpowder. Once the seat of Emperors in centuries past, Nuln has traded courtly glory for the roar of the foundry: its Imperial Gunnery School is the finest in the Old World, and from its smoke-wreathed works come the great cannon, mortars, and volley guns that give the Empire's armies their thunder.
The city is ruled by a Countess and governed in practice by its wealthy merchant and engineering guilds, whose fortunes rest on iron, coal, and black powder. Wealth and soot coat Nuln in equal measure. Its northern bank is a place of universities, opera houses, and marbled townhouses; its southern bank, across the river, festers with slums, tanneries, and the perpetual grime of industry, where the poor labour and the sewers run deep — deep enough that things are whispered to move in them.
Nuln's engineers are the Empire's proudest heretics against the old order, insisting that a common man with a well-made gun is worth any knight or monster. When the state regiments march, it is Nuln's artillery train that levels the field, and every cannon that batters a Chaos horde or shatters an orc Waaagh most likely began as molten iron poured in the foundries of the College of Engineering.