construction of a small stockaded fort in the early months of 1754. Governor Duquesne sent additional French forces under Claude-Pierre Pécaudy de Contrecœur to relieve Saint-Pierre during the same period, and Contrecœur led 500 men south from Fort Venango on April 5, 1754. These forces arrived at the fort on April 16, but Contrecœur generously allowed Trent's small company to withdraw. He purchased their construction tools to continue building what became Fort Duquesne. Early engagements Dinwiddie had ordered Washington to lead a larger force to assist Trent in his work, and Washington learned of Trent's retreat while he was en route. Mingo sachem Tanaghrisson had promised support to the British, so Washington continued toward Fort Duquesne and met with him. He then learned of a French scouting party in the area from a warrior sent by Tanaghrisson, so he added Tanaghrisson's dozen Mingo warriors to his own party. Washington's combined force of 52 ambushed 40 Canadiens (French colonists of New France) on the morning of May 28 in what became known as the Battle of Jumonville Glen. They killed many of the Canadiens, including their commanding officer Joseph Coulon de Jumonville, whose head was reportedly split open by Tanaghrisson with a tomahawk. Historian Fred Anderson suggests that Tanaghrisson was acting to gain the support of the British and to regain authority over his own people. They had been inclined to support the French, with whom they had long trading relationships. One of Tanaghrisson's men told Contrecoeur that Jumonville had been killed by British musket fire. Historians generally consider the Battle of Jumonville Glen as the opening battle of the French and Indian War in North America, and the start of hostilities in the Ohio valley. Following the battle, Washington pulled back several miles and established Fort Necessity, which the Canadians attacked under the command of Jumonville's brother at the Battle of Fort Necessity on July 3. Washington surrendered and negotiated a withdrawal under arms. One of his men reported that the Canadian force was accompanied by Shawnee, Delaware, and Mingo warriors—just those whom Tanaghrisson was seeking to influence. News of the two battles reached England in August. After several months of negotiations, the government of the Duke of Newcastle decided to send an army expedition the following year to dislodge the French. They chose Major General Edward Braddock to lead the expedition. Word of the British military plans leaked to