Château de Coucy

A castle stood on the Coucy spur long before the great one. The first mention dates from 920, a simple motte raised by Hervé, Bishop of Reims. In 964 Count Thibaud I of Blois seized it, earning a spell of excommunication until he passed the fortress to his son Eudes in 966, and in 1079 it was taken again by Albéric. The town below won its freedom from seigneurial power in 1197.

From about 1225 Enguerrand III, Lord of Coucy, rebuilt the castle on a scale meant to rival the kings of France. His enceinte formed an irregular trapezoid of 92 by 35 by 50 by 80 metres, its four corner towers 20 metres across with walls five metres thick — each as big as the keeps the French monarchy itself was then building. On the line of approach rose the donjon, some 54 metres high and over 31 metres across: the tallest keep in Europe, overtopping that of the Louvre by 20 metres. Viollet-le-Duc later wrote that beside this giant the biggest towers known in France, Italy or Germany were mere spindles. The pride matched the stone, caught in the family's rhyme: "I am not king, nor prince nor duke nor count; I am the Lord of Coucy."

Around 1380 Enguerrand VII — the diplomat whose life Barbara Tuchman took as the thread of her fourteenth-century study A Distant Mirror — softened the fortress, fitting out vast halls and a palace in the Gothic style. He died without a male heir in 1397, and in 1400 Louis d'Orléans bought the barony from his daughter for 400,000 livres tournois, to complete the defences of his duchy of Valois.

The purchase pulled Coucy into the civil war between Armagnacs and Burgundians. In the winter of 1411 the castle was besieged for three months by 600 men-at-arms under Waleran of Luxembourg, Count of Saint-Pol, acting for Duke John of Burgundy; its defender, Robert d'Esnes, known as Mansart, surrendered for want of food. The barony was attached to the French crown in 1498, under Louis XII.

During the Fronde the occupied castle refused to submit to Louis XIV, who ordered it dismantled and abandoned — carried out in 1652 under Mazarin's control. On 18 September 1692 an earthquake split the donjon from top to bottom, and at the Revolution the dismantled castle was sold as national property and worked as a stone quarry.

King Louis-Philippe bought the site in 1829 and the state acquired it in 1848. Architects including Viollet-le-Duc consolidated the ruins, ringing the great tower with an iron armature to make visits safe. Classed a monument historique in 1862, Coucy became one of the most visited monuments in France by the early twentieth century.

German troops occupied Coucy in September 1914 and held it as a military outpost, visited by dignitaries including Kaiser Wilhelm II. In March 1917, as the army withdrew to the Hindenburg Line under Operation Alberich, General Erich Ludendorff ordered the fortress destroyed: twenty-eight tonnes of cheddite were packed into the donjon and more than ten tonnes into the corner towers, with smaller charges at the town's three gates. The explosion came on 27 March 1917, while artillery devastated the town below — its thirteenth-century belfry and the church of Saint-Sauveur among the losses, only the church rebuilt after the war. No military necessity for the demolition was ever established, and the outrage was such that in April 1917 the ruins were declared "a memorial to barbarity".

War reparations paid to clear the towers and consolidate the walls, but the shattered keep was left where it fell, a compact heap of stone threaded with the great iron bars that once ringed it. Excavations from 2018 to 2020 uncovered the ducal kitchens built for Louis d'Orléans at the start of the fifteenth century, and the site, managed by the Centre des monuments nationaux, is open to visitors.