20 Baht - Rama IX Sirikit

Issued to mark the 75th birthday of Queen Sirikit, who had served as Regent during Bhumibol Adulyadej's periods of illness and monastic retreat — a constitutional role she exercised with notable political weight during the turbulent decades of Thai military coups and democratic transitions. The commemorative 20 Baht series produced under Rama IX is extensive, and KM#453 sits in a long run of similar issues from this period that collectively document the royal family's ceremonial calendar with unusual thoroughness.