In 1793, revolutionary France declares war on the Republic, and two years later occupies the Netherlands. The Patriots proclaim the Batavian Republic and abolish the institutions of the ancien régime. The Republic becomes a unitary state with a modern constitution
The restoration of William V's power as Stadholder as a result of Prussian intervention proved to be an illusion. The many Patriots who had fled to France and witnessed the revolution there were inspired to hope that they might likewise be able to bring about the overthrow of the ruling class in their own country. Events were triggered in 1792 by France's declaration of war on Austria and Prussia. French troops once again invaded the southern (Austrian) Netherlands, but were driven out again by Austrian forces. A year later, in 1793, France declared war on the Republic and on Britain and finally managed to occupy the southern Netherlands. In 1795 Utrecht and Amsterdam were also occupied by French troops and William V fled to England. Trees were planted throughout the Netherlands to celebrate the country's liberation. Whereas the revolution in France was accompanied by copious bloodshed, the overthrow of the Dutch ancien régime is sometimes referred to as the 'velvet revolution'. Throughout the country, the ruling members of the regent class were replaced by Patriots and the States General was replaced by a National Assembly elected by all members of the male population over the age of 20 and meeting certain other qualifications. Henceforth, the 'Batavian Republic' was to be ruled by the ideals of the French revolution.
In the same year, France and the Republic concluded the Treaty of The Hague. Among its stipulations was the provision that the Republic was to provide the French with the support of half of its land-based and naval forces, maintain 25,000 French troops, pay France reparation of 100 million guilders and cede to France the towns of Venlo and Maastricht. The imposition of even more stringent conditions was averted by the intervention of Pieter Paulus, president of the still surviving States General. The signing of the Treaty of The Hague caused Britain to declare war on the Republic and occupy the Dutch colonies.
In 1796 the National Assembly appointed a committee to draft a written constitution but opinions were initially divided on whether the traditional autonomy of the provinces should be replaced by a centralised unitary state. The strength of feeling on both sides led to a number of attempted coups d'état but ultimately, in 1798, the proponents of central government carried the day. Another innovation was the equal status accorded to all religious denominations, allowing non-Protestants to take an active part in political life for the first time since the Eighty Years' War.