British postage stamp featuring P&O Packet Steamer Peninsular 1888

This 3½p postage stamp was issued in 1974 by Great Britain to commemorate the centenary of the Universal Postal Union (UPU), which was established in 1874. The stamp features an illustration of the P&O Packet Steamer Peninsular from 1888, highlighting the important role of maritime transport in international mail delivery during that era. This commemorative stamp is part of a special series celebrating the UPU's contribution to international postal cooperation. Philatelists and postal history enthusiasts particularly value these UPU commemorative issues for their historical significance and connection to the development of global communication systems. The visible postmark from 1974 adds to its collectible appeal, showing it was actually used for its intended postal purpose.