The Canadian Bank of Commerce (The Commerce) opened for business on May 15, 1867 in Toronto. The head office and main branch were located on the corner of Yonge and Colborne in what would become Toronto's financial district. The Honourable William McMaster, a prominent Toronto businessman and philanthropist, was the principal founder of the bank and its first president. Concerned about Montreal's influence over the economy of Upper Canada, McMaster founded the bank mainly as competition for the Bank of Montreal. An aggressive businessman, he rapidly expanded the bank and its network of branches; by 1874 it had 24 branches, making it the largest bank headquartered in Ontario.

The Imperial Bank of Canada (The Imperial) opened in Toronto on March 18, 1875. Its original premises were located at 18 Toronto Street, not far from The Canadian Bank of Commerce. Henry Stark Howland, previously vice-president of The Commerce, was the principal founder and first president of the new bank.