Celts forded the Meuse here five centuries before Christ because the river ran shallow at this exact bend. The Romans, sometime in the first century AD, built a proper stone bridge during the reign of Augustus, threading the great road from Bavay to Cologne across the water. Roman Maastricht was modest: a small fort, a religious shrine, a bath, a granary. According to legend, Saint Servatius, the Armenian-born Bishop of Tongeren, died here in 384 and was buried along the road outside the castrum walls. Around 570 Bishop Monulph put a stone church over his grave, the first version of what is now the Basilica of Saint Servatius. For a few centuries Maastricht was a Christian diocese in its own right, before losing the title to nearby Liège.

Most Dutch towns can point to a date when they received city rights. Maastricht cannot. It grew into a city across centuries, and from 1204 onward it was formally co-ruled by two lords: the Prince-Bishop of Liège and the Duke of Brabant, each holding half of everything from the keys to the gates to the appointment of the magistrate. The arrangement survived sieges, a wholesale change of overlord when the Spanish crown took Brabant's place, and another change when the Dutch States General took the Spanish crown's place in 1632. In 1275 the old Roman bridge collapsed under the weight of a religious procession, taking with it, by some accounts, four hundred lives. The replacement, built slightly upstream and funded by selling church indulgences, is the Sint Servaasbrug, the oldest bridge in the Netherlands and still in use.

Sitting at a major river crossing in a contested borderland made Maastricht one of the most besieged cities in Europe. In June 1673, during the Franco-Dutch War, Louis XIV himself laid siege. Among his commanders was Sebastien Vauban, the great French military engineer, who used the siege of Maastricht to debut a systematic approach to attacking fortifications: parallel trenches, sapped progressively forward, that would remain the standard method until the twentieth century. On 25 June, preparing to storm the city through the Tongerse Poort, Captain-Lieutenant Charles de Batz de Castelmore took a musket ball and died. He is better remembered as the comte d'Artagnan, hero of Alexandre Dumas. The city kept building walls. Today the casemates, brick-and-limestone tunnels running fourteen kilometres beneath the fortifications, are open to guided tours.

In December 1991, the leaders of twelve European countries gathered in Maastricht's Provincial Government building on the banks of the Meuse and negotiated the treaty that would create the European Union, with all its citizenship rights and shared institutions, and lay the foundation for the single currency. The Treaty on European Union was signed in Maastricht on 7 February 1992. The location was chosen partly because Dutch Prime Minister Ruud Lubbers held the rotating EU presidency, partly because Maastricht sat at the symbolic centre of a city-region that already crossed three national borders. Walk along the Meuse today and you can still see the building where the negotiators argued through the night. The euro you pay with at the cafe a block away was born in those rooms.

Maastricht is, by Dutch standards, almost embarrassingly southern. Catholic in a Protestant country, multilingual in a country that mostly speaks Dutch and English, prone to throwing parties that last days. Carnival, called Vastelaovend in the local Limburgish, takes over the streets for three days each spring with brass bands called Zaate Herremeniekes, drunken-sounding ensembles that wander from cafe to cafe playing intentionally off-kilter marches. The 1,677 national heritage buildings, more than any Dutch city except Amsterdam, line the squares: the great Vrijthof with the Basilica of Saint Servatius and the red-painted limestone tower of Sint Janskerk, the tree-shaded Onze Lieve Vrouweplein with its eleventh-century basilica, the Markt where the seventeenth-century Town Hall stands as one of the masterpieces of Dutch Baroque. South of the centre rises Sint-Pietersberg, the chalk plateau full of caves where Maastricht's medieval churches were quarried, where Mosasaurs once swam, and where a city has watched its river bend for two thousand years.