Issued in 1970 to mark the centenary of Sir Rowland Hill (1795–1879), pioneer of the modern postal system, this stamp features the rare Flightless Rail of Inaccessible Island, one of the world’s most isolated bird species. The design combines local wildlife with a cameo portrait of Queen Elizabeth II, reflecting Tristan da Cunha’s unique philatelic identity under British administration. This issue is part of a notable commemorative series linking global postal history with the island’s distinctive natural heritage. Highly sought after by collectors of British Commonwealth, island issues, and wildlife-themed stamps.