British National Opera Company ended in 1929.
British Youth Opera was created in 1987.
Romanian National Opera was created in 1954.
Welsh National Opera was created in 1943.
Washington National Opera was created in 1957.
National Opera of Ukraine was created in 1867.
Cardell Bishop has written: 'Boston National Opera Company and Boston Theatre Opera Company' -- subject(s): Boston National Opera Company, Boston Theatre Opera Company
American Opera Company was created in 1937.
Canadian Opera Company was created in 1950.
Chicago Opera Company was created in 1940.
Birmingham Opera Company was created in 1987.
Boston Opera Company was created in 1908.