The new development of the contentious histories between Siam and Patani came in 1938, when Field Marshal Phibun came to power and began to implement a policy of Thai nationalism as part of his nation-building campaign. The government enforced the National Culture Act in which the most sensitive part was known as ratthaniyom, or the State Decrees. According to these laws, all Thais had to wear proper dress, and express modern behavior and etiquette when appearing in public places. In practice, it meant that Muslims could no longer carry their names in Malay or Arabic or dress in their Malay sarongs or headdresses. Moreover, they were required to use the Thai language for education and government offices. Finally, the use of the sharia court in the deep South was outlawed and replaced by Thai judicial courts.