British National Opera Company ended in 1929.
British Youth Opera was created in 1987.
National Opera of Ukraine was created in 1867.
Washington National Opera was created in 1957.
Romanian National Opera was created in 1954.
Welsh National Opera was created in 1943.
Cardell Bishop has written: 'Boston National Opera Company and Boston Theatre Opera Company' -- subject(s): Boston National Opera Company, Boston Theatre Opera Company
Berkshire Opera Company was created in 1962.
Philadelphia Opera Company was created in 1938.
Century Opera Company was created in 1913.
Opera Company of Boston was created in 1958.
Beecham Opera Company was created in 1915.