August 1, 1740.  Thomas Arne’s masque “Alfred”, the finale of which contains “Rule Britannia, was first produced, at Cliveden, England.

Thomas Augustine Arne (March 12, 1710 – March 5, 1778) was an English composer, best known for the popular patriotic song, “Rule Britannia“, which is still frequently sung, notably at the Last Night of the Proms, and also his musical settings of songs from the plays of William Shakespeare…

For more about him, please visit Wikipedia at: http://en.wikipedia.org/wiki/Thomas_Augustine_Arne