Pierre Guillaume Sayer (c. 1796 – sometime after May 1849) was a Métis fur trader whose trial was a turning point in the ending of the Hudson's Bay Company's (HBC) monopoly of the fur trade in North America. Sayer had been trading to Norman Kittson in Pembina, North Dakota, who was in direct competition to the HBC. Sayer was accused of illegal trading of furs and was brought to trial in Upper Fort Garry on May 17, 1849 by the Court of Assiniboia. He was backed by Métis leader Louis Riel Sr.. During the trial, a crowd of armed Métis men gathered outside the courtroom, ready to support their Métis brother peacefully or by force if necessary. Although found guilty of illegal trade by Judge Adam Thom, no fine or punishment was levied - many reports state it was due to the intimidating crowd gathered outside the courthouse. With the cry, "Le commerce est libre! Le commerce est libre!" ("Free Trade! Free Trade!"), the HBC could no longer use the courts to enforce their monopoly on the settlers of Red River. In 1870 the trade monopoly was abolished and trade in the region was opened to any entrepreneur. The company relinquished its ownership of Rupert's Land under the Rupert's Land Act of 1868 enacted by the Parliament of the newly formed Dominion of Canada. Nothing is known of Sayer's circumstances after his trial.
