Hostilities between Britain and France were soon renewed with the outbreak of the Seven Years' War in 1756. The 35th Regiment was deployed to America, where Monro relieved Lieutenant-Colonel William Eyre as commander of Fort William Henry in the Province of New York. That summer, the French General Louis-Joseph de Montcalm led a force of 8,000 French and Native troops in a weeklong Siege of Fort William Henry. Effectively cut off from the main British force, commanded by General Daniel Webb, the 1,500 man British garrison stood little chance of holding the fort once the French began formal siege operations on 3 August. Monro was forced to open negotiations with Montcalm on 9 August.