List of United Kingdom commemorative stamps
This list of United Kingdom commemorative stamps deals with commemorative stamps issued by Royal Mail, the postal administration of the United Kingdom. == History == Postage stamps were first used in the United Kingdom of Great Britain and Ireland on 6 May 1840, with the introduction of the world's first adhesive postage stamps, the Penny Black and Two Pence Blue.
Source: Wikipedia — List of United Kingdom commemorative stamps (CC BY-SA 4.0)