The area around the upper Great Lakes has been home to the Ojibwe people since prehistory. In 1815, William Fitzwilliam Owen surveyed the area and named the inlet after his older brother Admiral Edward Owen. A settlement called "Sydenham" was established in 1840 or 1841 by Charles Rankin in an area that had been inhabited by First Nations people. John Telfer settled here at that time and others followed. By 1846, the population was 150 and a sawmill and gristmill were operating. The name Sydenham continued even as the community became the seat for Grey County in 1852.