During the nineteenth century Siam (present-day Thailand) was trapped between British colonies to the west (Burma) and south (the Straits Settlements) and a French colony to the east (Cochin China), yet managed to retain its independence-the only SE Asian nation that succeeded in doing so.One consequence of this was that Siam did not establish a National Observatory or network of regional observatories, which were a conspicuous element of British colonialism (as witnessed, for example, in Australia, India and South Africa). Despite their designations as 'astronomical observatories', the primary function of these institutions was to provide a regulated local time service and meteorological data, but some also were involved in geomagnetic research, seismology, trigonometrical surveys and astronomical research. In Siam/Thailand, these non-astronomical functions were pursued by different Government departments or instrumentalities.Instead, Siam witnessed its first 'modern' astronomical observatories when European expeditions accepted invitations to come to Siam to observe the total solar eclipses of 1868, 1875 and 1929. These expeditions led to the emergence of academic astronomy in Thailand and the establishment of the nation's first permanent astronomical research observatory.In this paper, after reviewing British colonial observatory role models we will examine the nature of Siamese astronomy during the nineteenth century, the 1868, 1875 and 1929 European eclipse expeditions, and the subsequent development of professional astronomy in Siam. This culminated in the establishment of the National Astronomical Research Institute of Thailand in 2009 and the phenomenal growth of astronomy during the following decade, primarily under strong Royal patronage.
