section_path: History/Spread
section_name: Spread
paragraph_text: Spread
  
  The adoption by an ascendant Pagan paved the way for the calendar's adoption elsewhere in the Pagan Empire between the 11th and 13th centuries. The calendar first came to be used in peripheral regions or neighbouring states such as Arakan in the west and various Shan states in modern northern Thailand and Laos in the east, which adopted the calendar alongside folklore connected with the Burmese New Year. According to the Chiang Mai Chronicles and the Chiang Saen Chronicles, Chiang Mai and Chiang Saen and their tributary states of middle and upper Tai country (except Lamphun and Sukhothai) submitted to King Anawrahta and adopted the calendar in the mid-11th century in place of Mahāsakaraj, the standard calendar of the Khmer Empire. However, scholarship says the earliest evidence of Burmese calendar in modern Thailand dates only to the mid-13th century.
  
  While the use of the calendar appears to have spread southward to Sukhothai and eastward to Laotian states in the following centuries, the official adoption farther south by the Ayutthaya Kingdom and farther east by Lan Xang came only after King Bayinnaung 's conquests of those kingdoms in the 16th century. Subsequent Siamese kingdoms retained the Burmese calendar as the official calendar under the name of Chulasakarat (Pali: Culāsakaraj) until 1889. The Siamese adoption turned out to be the main catalyst for the calendar's usage in Cambodia, a periodic vassal of Siam between the 16th and 19th centuries. Likewise, the calendar spread to the Chittagong region of Bengal, which was dominated by the Arakanese Mrauk-U Kingdom from the 15th to 17th centuries.