The world’s first postage stamp was issued in Great Britain on the 1st of May, 1840 – and became valid 5 days later on the 6th. The adhesive stamp, nicknamed the “Penny Black” showed a profile of reigning monarch Queen Victoria along with its one penny denomination.
The issuance of the Penny Black marked a switch to pre-payment of postage, from the previous system which was paid on delivery based on the distance the letter had travelled.