"Chiamay Lacus": Lan Na's legendary Great Lake

Part of Ancient Chiang Mai

The copious river of Menam behold,
And the great lake Chiamay from whence 'tis roll'd.

Luís vaz de Camões, Os Lusiades, Lisbon, 1572

Somewhere around 200 million years ago the super-continent of Pangaea (which means "all land" in Greek), subject to the almost inconceivable forces of tectonic shift, broke up into separate continents. Initially - according to the geologists - there were two such giant continents, Laurasia to the north and Gondwana to the south. Subsequently, around 140 million years ago, a huge landmass, which was eventually to become the South Asian sub-continent, broke off from Gondwana and began drifting north towards Asia. The eventual collision, which happened about 70 million years ago, resulted in a slow but cataclysmic buckling of the Indo-Australian and Eurasian plates, causing the birth of the Himalayas, a process that continues today.

David Henley / CPA

Late afternoon on the Irrawaddy River at Mandalay.

As the Himalayas rose to create the high Tibetan Plateau, so glaciers were formed which in turn gave birth to many of the world's greatest rivers. A number of these - the Yangtze, Mekong, Salween and Brahmaputra - run southeast from the plateau, forced by the geography of cataclysmic collision to flow through narrow parallel valleys, very close to each other but separated by high mountain ranges, in the region of western Yunnan known as the "Land of Great Corrugations". The Yangtze then runs off east into the China Sea, but the Mekong and the Salween run south, through the lands of Indochina. Here lesser, but still mighty rivers such as the Maenam Chaophraya and the Irrawaddy, also products of the great Himalayan collision, accompany them in their various courses to the South China Sea, Gulf of Thailand and Bay of Bengal.

Until fairly recently nobody had any idea where these great rivers originated. It was somewhere in the mountains to the north, no doubt, but exactly where remained uncertain. The exact source of the Mekong, for example, was not finally determined until 1999. A similar situation once applied in Africa with regard to the Nile. Geographers long thought this mighty river to rise in two great lakes located in the Lunae Montes, the fabulous Mountains of the Moon, located at the unexplored heart of the Dark Continent. This belief can be traced to the middle of the 1st century AD, when the Greek merchant and traveller Diogenes brought back a report of 'two great lakes and a snowy range of mountains whence the Nile draws its twin sources'. The Syrian geographer Marinus of Tyre duly recorded this, and it was from these learned records that the geographer Ptolemy produced his celebrated 2nd century map.

It is purely speculation, but it might well be that Ptolemy's map influenced early European voyagers to Southeast Asia. It is easy to imagine that the first Portuguese sailors to visit the region, followed shortly by the Dutch, British and French, drew navigational charts of the Irrawaddy, Salween and Maenam River mouths and asked the locals where the rivers originated. But of course the locals didn't know - just as the denizens of the high Tibetan Plateau, where the rivers rose, had know idea to where they ultimately flowed. In any case, at some time during the 16th century, soon after European sailors first visited Southeast Asia, an idea was conceived, based, probably, on erroneous local reports, that these rivers - like the Nile in Africa - rose somewhere in the heart of Asia, and that their common source was a great lake. And the name given to that lake was Chiamay Lacus, the Lake of Chiang Mai.

Early 18th century map of India beyong the Ganges showing "Chiamai Lacus" (top centre).

The earliest known mention of the spurious Lake Chiang Mai occurs in a report of the Portuguese Antonio de Faria y Sousa dating from 1542-43. Faria y Sousa was captain of a small ship sailing through the Gulf of Siam from Pattani towards Cambodia. The geography is confusing, because the place names in his report are virtually unidentifiable and seem to bear no relation to known Southeast Asian ports. Somewhere along the coast of Siam he anchored off a small town he identifies as Tayquileu - it seems idle to speculate as to its identity, but it was probably at or near the mouth of the Maneam Chaophraya. The locals informed him that the river was deep and navigable for 80 leagues, and that it originated further to the north in 'the great lake of... Chiamay, whence spring four great rivers. That lake is 180 leagues in circumference, and the country round abounds in mines of silver, copper, tin, and lead'.

David Henley / CPA

Sunset on the Chaophraya River, Bangkok.

Just two years later mention of Lake Chiang Mai occurs in Mendez de Pinto's Peregrinação (1544), a work of so widely doubted authenticity that its author has been dubbed Mendax de Pinto, or "Prince of Liars". Pinto reports that during his travels he visited 'the Lake of Singipamor, which ordinarily is called Chiammay... Out of this lake do four very large and deep rivers proceed, whereof the first... runs eastwards through all the kingdoms of Sornau and Siam... the second, Jangumaa, disimbowking into the sea by the Bar of Martabano in the Kingdom of Pegu'. Pinto's first river is clearly the Maenam Chaophraya, while the second - its name presumably, like Chiammay, a variant of Chiang Mai - must be the Salween. As with the lake itself, Pinto's geography remains (perhaps understandably) dubious.

By 1552 the legend of Lake Chiang Mai was already well established, for in that year João de Barros reports quite specifically in his Decadas de Asia that: 'the lake of Chiamai stands to the northward [of the Gulf of Siam], 200 leagues in the interior. From it issue six notable streams, three of which combining with others form the great river which passes through the midst of Siam [the Maenam Chaophraya], whilst the other three discharge into the Gulf of Bengala [the Salween, Irrawaddy and Brahmaputra]'. The authenticity of Lake Chiang Mai aside, de Barros clearly had a reasonable grasp of the geography of the region, which he likens to a left hand, placed palm downwards. 'And as regards the western part, following always the sinew of the forefinger, it will correspond with the ranges of mountains running from north to south along which lie the Kingdom of Avá, and Bremá, and Jangomá'.

By 1572 'Lake Chiamay' was even represented in European verse, when the celebrated Lisbon poet Luís vaz de Camões composed his Os Lusiades to celebrate the expedition and achievements of the great Portuguese navigator Vasco da Gama (1460-1524) in the Indian Ocean: 'Olha o rio Menão, que se derrama, do grande lago, que Chiamai se chama'. (The English translation given above was made by Richard Fanshaw in 1655 and printed in London for Humphrey Moseley at the Prince's Arms in St Paul's Churchyard).

Because of Chiang Mai's physical isolation from the coast and the very rare visits paid to it by Westerners, the myth of Lake Chiang Mai continued well into the 17th century, and as such it is represented on most or all European maps of the time. As late as 1652 in his Cosmographie the Englishman Peter Heylin felt confident enough to record that: 'the Countrey of these Brames [Brahmins/Buddhists]... extendeth Northwards from the nearest Peguan Kingdomes... watered with many great and remarkable Rivers, issuing from the Lake Chiamay, which though 600 miles from the Sea, and emptying itself continually into so many Channels, contains 400 miles in compass, and is nevertheless full of waters for the one or the other'.

So when was the myth of "Lake Chiang Mai" finally disproved? It's difficult to say with any accuracy. The source of each of the great rivers involved would eventually be traced, none of them originating in a lake, let alone a single great body of water in the vicinity of Chiang Mai. Long before then, however, the legend had been laid to rest. British commercial and scientific interest in the Upper Burma-Northern Thailand region expanded significantly during the late 18th and early 19th century, and it is possible to state with confidence that by 1837, at the time of the McLeod and Richardson diplomatic missions to Chiang Mai and Kengtung, the notion of a "Lake Chiang Mai" had been definitively disproved. Consequently, and rather sadly, today Chiamay Lacus remains nothing more than a cartographic curiosity.

Text by Andrew Forbes, images by David Henley. © CPA Media, 2005