Consolidation of central administrative unit names

During the thesaphiban reforms at the beginning of the 20th century, the central administration hierarchy Monthon, Changwat, Amphoe, Tambon, Muban was created all over the country - however the levels below Monthon differed in the various parts of the country. Most notably, until 1916 the provinces were usually named Mueang since these were the historic precursor of the modern-day provinces.

Thus the announcement ประกาศกระทรวงมหาดไทย เรื่อง ทรงพระกรุณาโปรดเกล้า ฯ ให้เปลี่ยนคำว่าเมืองเรียกว่าจังหวัด from May 1916 changes two things - the Mueang (เมือง) are thereafter called Changwat (จังหวัด) and the Mueang governor (ผู้ว่าราชการเมือง) is thereafter known as province governor (ผู้ว่าราชการจังหวัด). I am not sure what the other text of this three-paged document is about, if I don't misunderstand it the use of "Amphoe Mueang" is also defined in there.

However actually the term "changwat" is a bit older already. I just recently discovered another announcement from 1908, in which for the Monthon Phayap, i.e. the area now known as northern Thailand, the modern names were introduced already. In same order as defined in the document these are

• District officer นายแขวง to นายอำเภอ
• District แขวง to อำเภอ
• Subdistrict headman นายแคว้น to กำนัน
• Subdistrict แคว้น to ตำบล
• Village headman แก่บ้าน to ผู้ใหญ่บ้าน
• Province บริเวณ to จังหวัด

The last one is the most interesting one. I already posted about another announcement which made me understand that in fact the Boriwen were the procursor of the provinces, also dating from 1908 and covering the area of Monthon Udon. In there the Boriwen were however renamed to Mueang. The only remaining Monthon which had Boriwen is Isan, which covered the southeastern part of the Khorat plateau, I only haven't yet found the Royal Gazette announcement changing the Boriwen in there to either Mueang or Changwat.