Editing 1840s (section)

==== Siam and Vietnam ====
The [[Siamese–Vietnamese War (1841–1845)|Siamese-Vietnamese War (1841–1845)]] in [[Post-Angkor period|Cambodia]] erupted between Vietnam (then under the rule of the [[Nguyễn dynasty]]) and Siam (under the [[Chakri dynasty|House of Chakri]]). In the increasingly confrontational rivalry between Vietnam and Siam, the conflict was triggered by Vietnam's absorption of Cambodia and the demotion of the Khmer monarchs. Siam under [[Rama III]] seized the opportunity to intervene as the tide of Khmer discontent rose against Vietnamese rule.<ref name="Schliesinger2017">{{cite book|url=https://books.google.com/books?id=8obRDQAAQBAJ&pg=PA106|title=The Chong People: A Pearic-Speaking Group of Southeastern Thailand and Their Kin in the Region|author=Joachim Schliesinger|date=2 January 2017|publisher=Booksmango|isbn=978-1-63323-988-3|pages=106–}}</ref>

Emperors [[Minh Mạng]], [[Thiệu Trị]] and [[Tự Đức]] ruled Vietnam during the 1840s under the Nguyễn dynasty.