It is the 90th anniversary of the BBC World Service. Broadcasting to countries behind the Iron Curtain without a free or independent media between 1947 and 1991 was arguably the service’s finest hour.

The corporation was on the front line of the information war as the BBC’s former Moscow correspondent Bridget Kendall recalls.

Programmes such as the German Service’s Letters Without Signatures created a sense of community among isolated East Germans who could not air their views publicly at home.

Meanwhile, Peter Udell, the former controller of European Services, had the challenge of trying to overcome the Soviet censors. Produced and presented by Josephine McDermott.

BBC World Service – Witness History, The BBC broadcasting through the Iron Curtain