Cayamay Lactus – Apocryphal Source of the five Great River Systems of Southeast Asia

For nearly four hundred years many maps of Asia,reassociated with local rivers such as the Irrawaddy,
and particularly India and Southeast Asia, depicted anthe Dharla, the Mekong, and the Chao Phraya.
enormous lake far to the northeast of the Bay ofFrom a European perspective, associating these
Bengal. This lake, alternately called Chiamay,rivers systems with one another and with a single
Chiam-may, Chian-nay, or Cayamay, is postulated tosource is an almost natural assumption. All five rivers
be the source of four to five of the great Southeastbear a great deal of similarity. That is, all seem to
Asian river systems, the Irrawaddy, the Dharla, theoriginate from roughly the same area, all flow along
Chao Phraya, the Bramaputra, and the Mekong.roughly parallel courses, and all have enormous fluvial
Today we know that the Lago de Chiamay is entirelyvolume. Associating a great lake with said source is
non-existent, but where did this persistent mythequally natural. Given the size and orientation of these
come from?river systems, one naturally speculates that the
1685 Bormeester Map of the World showing Chiamaysource lake itself must be enormous. Such speculation
The earliest reference to the Lago de Chiamay thatwas not uncommon for map makers working in the
we have been able to come across is the c. 155018th century and earlier. Cartographers, who rarely
geographical study produced by Jao de Barros.traveled the world themselves, had the difficult job
Barros, who is not known to have traveled to theof piecing together and interpreting various vague
orient himself, compiled his geography from reportsand often contradictory traveler’s accounts as
from Portugese explorers in the region, whowell as reconciling such new information with
themselves no doubt extracted many of their ideasaccepted mappings.
about the remote interior of Asia from indigenousWhatever the original source for the Lago de
authorities. His most likely source for our purposes isChiamay may have been, it begins appearing on maps
most likely Fernao Mendez Pinto. Today the Barrosas early as the Gastaldi map of 1550 (though some
geography is unfortunately lost, but some of itsspeculate that this map was actually drawn a few
commentary survives via G. B. Ramusio and his 1554years earlier). The Lago was embraced by Ortelius in
edition of “Navigationi et viaggi”. While somehis c. 1570 mappings of Asia and was eventually
have argued that Ramusio could not have possiblyassociated with various hopeful fantasies of a river
have had access to Barros’ commentary, as itpassage through central Asia to the North Sea.
had not been published at the time, Ramusio himselfAlmost all subsequent mappings until the late 18th
provides clear reference that he did in fact have ancentury included the Lago de Chiamay in various
unpublished Barros manuscript. Ramusio includesforms. Later, as explorers began to penetrate the
several maps in his “Navigationi et viaggi”region with greater regularity, Chiamatwas at various
that were drawn around 1550 and depict the Lago.point associated with any lake discovered in the area,
Fernao Mendez Pinto, Barros most likely source andincluding Koko Nor (Qinghai Lake) in China and the
the lake’s supposed “discoverer”, is theactual Lake Manasarovar in Tibet. By the late 18th
only European who claims to have visited the lakecentury the lake had moved far west of its original
itself. Pinto apparently discovered the lake in 1744.location and been reduced to a fraction of its original
Generally speaking, while Barros was well respectedsize. By the 19th century, it disappeared entirely.
in his day, Pinto is considered an unreliable geographerThe source of the name itself, “Chiamay”
at best and at worse has been dubbed themay be derived from Pinto’s original discovery of
“prince of fiction”. Why this is the case whenthe lake in the records at the Royal court in Siam.
he was without a doubt actually in Siam, may bePinto was told of a royal raid to conquer and claim
explainable when his own sources are evaluated. PintoChiang Mai, once the Capital of the Lanna Kingdom.
may have heard about the lake in the Royal Court of1848 Homann Heirs Map of India & Southeast
Siam, one of the kings of which is said to haveAsia
invaded Chiamay and captured many cities around it.The city of Chaing Mai, now fully part of Thailand
1540 Seutter Map of India, Tibet and Southeast Asiawas founded in 1296 and was frequently invaded and
That Pinto derived much of his geography from localconquered by both the Siamese and Burmese
sources is highly likely. What he and his readers backempires before being formally incorporated into the
in Europe may not have counted on is the presenceSiamese empire in the late 18th century. Though
of a mythical and semi-mythical Hindu-Buddhistthere is no lake near Chiang Mai, Pinto, who is not
geography overlaying the actual geography. Hindu andknown for reliability, may have misinterpreted what
related Buddhist mythology consider Lakehe was told. The Lago de Chiamay is most likely the
Manasarovar and Lake Rakshastal, in modern dayresult of Pinto’s misunderstanding of stories from
Tibet, to be the spiritual source of four religiously andthe royal court of Siam, misassociations regarding the
geographically important subcontinent rivers, theBuddhist-Hindu mythology associated with Lake
Brahmaputra, the Karnali, the Indus and the Sutlej. AsManasarovar, and natural assumptions based upon
the Hindu-Buddhist culture expanded into southeastthe observable similarities of the great southeast
Asia, these four rivers and their source lake wereAsian river systems.