File:Flag of the United Kingdom.png

Summary
This work is in the public domain worldwide. This is because either: It is a photograph created by the United Kingdom Government taken prior to 1 June 1957; or It is an engraving or photograph created by the United Kingdom Government and commercially published more than 50 years ago; or It is any other work created by the United Kingdom Government published more than 50 years ago. See Copyright, Crown copyright artistic works (archived resource) and HMSO Email Reply.

http://en.wikipedia.org/wiki/File:Flag_of_the_United_Kingdom.svg