The first of the Thai cultural mandates was issued, officially changing the country's name from Siam to Thailand.

The cultural mandates or state decrees were a series of twelve edicts issued between 1939 and 1942 by the government of Field Marshal Plaek Phibunsongkhram during his first term as prime minister and military dictator of Thailand. The mandates aimed to create a uniform and "civilized" Thai culture at the time when the country was one of the Axis powers. Many of the mandates' practices were a result of Thailand entering World War II, and they remain in effect.