At the time of the Reformation in the 16th century, many of the inhabitants of Montpellier became Protestants (or Huguenots as they were known in France) and the city became a stronghold of Protestant resistance to the Catholic French crown. In 1622, King Louis XIII besieged the city which surrendered after a two-month siege (Siege of Montpellier), afterwards building the Citadel of Montpellier to secure it. Louis XIV made Montpellier capital of Bas Languedoc, and the town started to embellish itself, by building the Promenade du Peyrou, the Esplanade and a large number of houses in the historic centre. After the French Revolution, the city became the capital of the much smaller Hérault.