The treaty, signed on February 24, 1826, not only ended the First Anglo-Burmese War but also compelled Burma to cede Arakan, Assam, Manipur and Tenasserim to British India ...
Indigenous Organisations observe ‘Black Day’ on 200th anniversary of Treaty of Yandabo, terming it a turning point in Assam’s loss of sovereignty.
https://siris-libraries.si.edu/ipac20/ipac.jsp?&profile=liball&source=~!silibraries&uri=full=3100001~!234840~!0#focus ...