The city’s decline from the second half of the 14th Century seemed inexorable. The merchant oligarchy had increasing difficulty in running the "Republic of Montpellier" and a new urban elite of royal officers and lawyers appeared.
Montpellier became a city of Supreme Courts in which, from now on, lawyers and holders of office carried more weight than merchants and artisans.
In addition to these changes, there was religious conflict between Catholics and Protestants. This caused a great deal of bloodshed throughout the 16th Century, ending only with the intervention of Louis XIII’s troops and the siege of Montpellier in 1622.
With the return of peace, the monarchy, supported by the Counter-Reformation, imposed a vast project on the devastated city, transforming it into a modern town capable of taking on the role of capital of the French province of The Languedoc.
The most spectacular changes occurred during the reign of Louis XIV and under the supervision of Richelieu. The construction of the promenade on the Peyrou Hill gave impetus to a transformation of the town that freed it from its medieval shackles. Elegant private mansions were built everywhere, along with follies, religious (the Saint-Denis and Pénitents Blancs churches), military (construction of a fort by Vauban…) and public buildings (theatre, general hospital, etc.).
At the end of the 17th Century, an “Arc de Triomphe” was built to the glory of Louis XIV at the main entrance to the city, opposite the new promenade.
Such feverish change also helped towards economic revival: textiles, leather and winegrowing all took part in the renaissance.
Montpellier then entered the 18th Century – the age of Enlightenment. The old Babote watchtower was closed down and an astronomical observatory was built on the spot. In 1764, the Saint Clément aqueduct (Les Arceaux) brought water to Montpellier from the source of the Lez. For several decades this solved one of the city’s recurrent problems since its foundation: the supply of drinking water.