The project to regroup the supporters of the Patriot Revolt in exile in France at the end of the 1780s was born in December 1791.
However, France was not yet at war with the Dutch Republic and the French government rejected the idea of a Batavian legion.
In July 1792 Quint Ondaatje sought help from Johan Valckenaer and Court Lambertus of Beyma and proposed the formation of a Batavian Legion, assisting in an invasion into the Dutch Republic by general Dumouriez.
The minister for war, Dumouriez, advanced 700,000 livres for its formation and it gathered in the Dunkirk region under the command of lieutenant-colonel Herman Daendels.
On 17 February 1793, the French troops and the Batavian Legion crossed the border; Ondaatje was present during the Siege of Breda by Westermann,[2] occupied by an army of Sans-Culottes that lacked almost everything.