In the spring of 1660, the colony of New France verged on collapse. Iroquois forces had seized several fur shipments in the previous year and taken them to the Dutch traders at Fort Nassau (Albany, New York). The Iroquois controlled the St. Lawrence and Ottawa rivers and had severed contact between the French and their Native allies to the west.
On 15 April, a young officer of the Montreal militia, Captain Adam Dollard, Sieur des Ormeaux, formulated a daring plan to defeat the Iroquois. He would lead a force of 16 militia and 42 Huron and Algonquin warriors up the Ottawa River to ambush Iroquois canoes carrying furs to the Dutch. He would then bring the furs to Montreal for shipment to France.
With the Governor's approval, Dollard's force travelled up the Ottawa River undetected and set up an ambush near Long Sault. On 2 May 1660, the force attacked a small force of 13 Onondaga (one of the Five Nations or Iroquois Confederacy). The Iroquois canoes carried no furs but were scouts for a far larger force preparing to launch an attack on Montreal. Within hours, the main Iroquois force arrived at Long Sault. Dollard's force had hastily occupied an abandoned Algonquin wooden palisade. The Iroquois immediately mounted an assault on the tiny force.
Dollard's men repulsed numerous attacks over the next eight days. Although 30 Huron and Algonquin deserted, the remainder determined to continue fighting. On the final day, 10 May 1660, Dollard and his men filled a keg of gunpowder with musket balls. They lit the fuse and attempted to hurl it over the palisade into the ranks of the attacking Iroquois. The heavy keg caught on a branch and fell back into the midst of the defenders. Seconds later it exploded, killing most of Dollard's men. Within moments the Iroquois stormed into the palisade. Five Huron managed to escape and make their way back to Montreal.
The heroic defence at Long Sault, which became one of the most famous incidents in New France's history, inflicted such heavy casualties on the Iroquois force that they abandoned their attack on Montreal.