During the American invasion, the Patriots briefly held Montreal which was commanded by Colonel Moses Hazen. Because of concerns about British activity to the west, Hazen sent 400 troops commanded by Colonel Timothy Bedel of Bedel's Regiment to occupy the Cedars.
The command of the American garrison at Montreal was temporarily taken up by Col. Moses Hazen while Col. Benadict Arnold traveled northward to join Brig. Gen. John Thomas' troops. Reports of British activity to the west caused Hazen to order Col. Timothy Bedel and a 400-man force to defend The Cedars. The post was on the St. Lawrence River, 30 miles west of Montreal.
On May 15, Bedel learned that a British force of of 150 British troops of the 8th Regiment of Foot and about 500 Iroquois commanded by Captain George Forster was headed toward The Cedars. Bedel left Maj. Isaac Butterfield in charge of the post and then left for Montreal for reinforcements. Hazen directed Maj. Henry Sherburne's relief force of 100 men toward The Cedars, but it arrived too late.
On May 16, Sherburne's relief force started towards The Cedars. Arnold strated to gather a larger force to send a little while later. Forster's British force confronted the smaller American garrison and Butterfield surrendered the garrison without a fight. He agreed to a cartel with Forster in which that Butterfield recieved assurances that the Americans would be protected from the Indians accompanying him in exchange for the British to aquire the post.
On May 20, Sherburne's relief force landed at Quinze Chiens, located 9 miles from The Cedars. They did not know that Butterfield had already surrendered. They marched into a British ambush about 4 miles from The Cedars. They fought the British for about 40 minutes before they were forced to surrender. The British executed 2 prisoners that night and 5 were later tortured and killed by the Indians.
On May 26, the British force had moved their camp to Quinze Chiens when Forster learned of Arnold's relief column was approaching. Forster sent Sherburne to Arnold to let him know about the earlier agreed-upon cartel with Butterfield. If Arnold disregarded the cartel, Forster would release the prisoners to the Indians. Arnold agreed to take the prisoners and return to Montreal.
Blame for the defeat was initially placed on Bedel by Arnold. As a result, Bedel was removed from command. Following the surrender at the Cedars some of the American prisoners were quickly exchanged for British soldiers captured at the Battle of Fort St. Jean.