The world's first postage stamps were issued in Great Britain in May, 1840. The stamps, known as the Penny Black and the Two-Penny Blue, featured an identical design, a profile of young Queen Victoria. They were made possible by some ideas that we take for granted but were revolutionary back in the 1800's: that postage rates should be uniform and based on weight rather than distance, and that postage should be paid by the sender (rather than the receiver). (The New Book of Knowledge by Grolier)
