Mike Williams asks why do we fly flags? They have many uses, from identifying symbols to signalling tools. But why a piece of cloth? Because it moves in the breeze, and movement catches the eye. The first flags were used by warlords in China, as China wove silk.

Mike goes to the National Maritime Museum in Greenwich to find out about the many uses of flags in merchant fleets and the navy, and hears from the designer of the new South African flag that it was all done in such a rush that his sketch had to be faxed and coloured in at the other end, to get the approval of Nelson Mandela who happened to be in a meeting in another city. Mike also talks to a German artist who replaced the two Stars and Stripes on the Brooklyn Bridge with white versions, and to the Russian who planted a titanium Russian flag on the floor of the Arctic ocean, to claim it for his country.

Produced by Arlene Gregorius.

(Photo: Faithfuls with flags of different countries gather at a beach. Credit: Tasso Marcelo/AFP/Getty Images)