The Times of London has an interesting article on censorship of the performance of plays in England, including historical discussions. 

A disgusting feast of filth?  by Anthony Burton. The Times. September18, 2008.

http://business.timesonline.co.uk/tol/business/law/article4775754.ece?&EMC-Bltn=B9QEK9

Excerpts from the article:

It was the Licensing Act of 1737 that gave the Lord Chamberlain the role of arbiter of theatrical taste. The role, held until 1968, was introduced by the Prime Minister Robert Walpole to gag his theatrical critics, in particular Henry Fielding, by banning any offensive reference to a living person. So from the 18th century every British playwright had to obtain a licence for the public performance of a play … By September 1968 the Theatres Act was in force and the censor banished.