This commemorative stamp was issued by Tristan da Cunha in 1990 to celebrate the 90th birthday of Queen Elizabeth The Queen Mother (1900–1990). The design features a portrait of the Queen Mother holding a bouquet, with the dates 1900–1990 marking her long life and royal service. The crown and “ER” (Elizabeth Regina) monogram symbolize the British monarchy. As Tristan da Cunha is a British Overseas Territory, royal commemorative issues are an important part of its philatelic history and are popular among collectors of Commonwealth and royal-themed stamps.