 Even if reunification should prove impossible, no armistice between the Dutch and Belgians had been signed and William believed that a successful military campaign against the Belgians would improve his position in future diplomatic negotiations.Therefore, when William learned that the rebels had asked Leopold of Saxe-Coburg to be their king, he began to prepare his invasion.In 1831, a 50,000-strong Dutch force was built up near the Belgian border in North Brabant, allegedly to protect the frontier.