600 Baht - Rama IX 50th Birthday of Princess Sirindhorn

Princess Maha Chakri Sirindhorn, born in 1955, was granted the title Chao Fa — a rank reserved for children of a king and queen — and has accumulated a degree of genuine public affection unusual even within the Thai royal family, owing to her decades of work in rural education and development projects. The 2005 issue marking her 50th birthday falls within a long series of Thai commemorative silver pieces authorized through the Treasury Department, a program that expanded aggressively from the 1980s onward. Y#427 is catalogued among dozens of similar commemoratives from this period, many sharing the same 925 silver specification.