Thai National Flag Day (28 September)

This study presents the background of Thai National Flag Day, commemorated annually on 28 September, the date in 1917 when King Vajiravudh (Rama VI) officially proclaimed the Tricolour Flag (Thong Trairong) as the national flag of Siam. It traces the development of Thai national flags, from the use of the white elephant flag to the period of World War I, when Siam joined the Allies and adopted the Tricolour. The article emphasizes King Vajiravudh’s vision and direct role in designing the national flag, while highlighting the Fine Arts Department’s role in preserving and disseminating historical records. It also situates the flag reform within the broader modernization policies of King Rama VI and notes the 2016 Cabinet resolution designating 28 September as Thai National Flag Day.