Detail of a British map dating from the early 19th century. Burma's Tenasserim Province (pink) is marked as being British and was seized by Britain after the First Anglo-Burmese War (1824-1826).

The geography is very imperfect; the first Brirish surveying teams into 'Laos Land' not being dispatched until the missions of McLeod and Richardson (1836-37). Chiang Mai; the Lan Na capital; at this time under the rule of Chao Phuttawong (1825-46); is identified as 'Saymamay'. The Lao capital; Vientiane; conquered and despoiled by Siam in 1828; is identified as Lanchang; and placed on the wrong; west bank of the Mekong River. Luang Prabang; to the north; is probably identified as (the more northerly) M. Loun.

Hanoi; the capital of Tonkin to the Northeast; is identified (puzzlingly) as 'Kesho' or 'Tongquin'; the latter being 'Eastern Capital' in Vietnamese. To the south; is still identified as the old capital of Siam; 'Yuthia' (Ayutthaya); although the capital was moved to Bangkok in 1782.

The River Salween is shown as the frontier between the Lan Na Kingdom and Burma; while the northernmost part of Lan Na is shown to extend north; into the Shan States in the region of Kengtung