Wikipedia:Selected anniversaries/June 26
June 26: Flag Day in Romania; Sunthorn Phu Day in Thailand
- 1409 - Western Schism: Pope Alexander V was crowned after the Council of Pisa, joining Pope Gregory XII in Rome and Avignon Pope Benedict XIII in Avignon.
- 1940 - Under the Molotov-Ribbentrop Pact, the Soviet Union gave Romania an ultimatum requiring it to cede territory.
- 1945 - The United Nations Charter was signed in San Francisco, California.
- 1959 - The Saint Lawrence Seaway, a system of canals connecting the Great Lakes to the Atlantic Ocean, was officially opened.
- 1963 - John F. Kennedy gave his "Ich bin ein Berliner" speech.
- 1976 - The CN Tower (pictured), the tallest freestanding structure on land, was opened to the public in Toronto.