Aix-la-Chapelle (Aiks-la-shapel'; Ger. Aachen), a town of Rhenish Prussia, is situated in a fertile hollow, surrounded by heights, and watered by the Wurm, 39 miles W. by S. of Cologne. Pop. (1867) 67,923; (1900) 135,245, of whom not 7 per cent. are Protestants. Aix is the centre of a valuable coal district, and of numerous thriving manufactories, especially for spinning and weaving woollen fabrics, for needle and pin making, and for machinery, bells, glass buttons, chemicals, and cigars. Charlemagne founded its world-wide celebrity; in 814 it became his grave, the spot being marked with a stone. In 796 he had rebuilt the imperial palace, on whose site the present town-house was built in 1353, as well as the chapel which forms the nucleus of the cathedral. This ancient cathedral is in the form of an octagon, which, with various additions round it, forms on the outside a sixteen-sided figure. The so-called 'great relics,' shown once in seven years, attract thousands of strangers. Much has of late years been done to restore this venerable pile. The columns brought by Charlemagne from the palace of the Exarch at Ravenna, had been carried off by the French; but most of them were restored at the Peace of Paris. The town-house, on the market-place, is flanked by two towers older than itself. In its coronation-hall, thirty-five German emperors and eleven empresses have celebrated their coronation banquet, and the walls have been decorated with frescoes of scenes from the life of Charlemagne. Before the town-house stands a beautiful fountain, with a bronze statue of Charlemagne. Aix-la-Chapelle now possesses broad streets, many fine public buildings, tasteful churches, and luxurious hotels; and from being a quiet old city of historical interest, has become a busy centre of manufacturing industry.
The mineral springs, of which six are hot and two cold, were known in the time of Charlemagne. The temperature of the hot springs varies from 111° to 136° F.; they are efficacious in cases of gout, rheumatism, cutaneous diseases, etc. The cold springs are chalybeate.
The name of the place is derived from the springs, for which it has been always famous. Charlemagne granted extraordinary privileges to this city, which in the middle ages contained more than 100,000 inhabitants. Seventeen imperial diets and eleven provincial councils were held within its walls. The removal of the coronations to Frankfort (1531), the religious contests of the 16th and 17th centuries, a great fire which in 1656 consumed 4000 houses, combined with other causes to bring into decay this once flourishing community. In 1793 and 1794, Aix-la-Chapelle was occupied by the French; and by the treaties concluded at Campo Formio and Luneville it was formally ceded to France, until in 1815 it fell to Prussia.