The town of London was the major centre, although it was a separate electoral district, surrounded by Middlesex.

Those boundaries had originally been set by a proclamation of the first Lieutenant Governor of Upper Canada, John Graves Simcoe, in 1792, under the name of the County of Suffolk: The boundaries had been further defined by a statute of Upper Canada in 1798, which re-named Suffolk county to be Middlesex county: Since Middlesex was not changed by the Union Act, those boundaries continued to be used for the new electoral district.

[9] It was succeeded by three electoral districts in both the House of Commons of Canada[10] and the Legislative Assembly of Ontario.

[11] This article incorporates text from this source, which is in the public domain: Proclamation, Lieutenant Governor John Graves Simcoe, July 16, 1792.

This article incorporates text from this source, which is in the public domain: An act for the better division of this province, SUC 1798, c. 5, s. 36.