Emblem of the Royal House of Chakri, the ruling Dynasty of Thailand (formerly Siam), founded in 1782. The Emblem depicts a 'Chakra' (disc) and a 'Trisula' (trident) intertwined.  Both of these objects are weapons of Vishunu (of which the Kings of Siam believe themselves to be 'Avatars'). The symbols also directly relates to King Rama I's pre coronation title of "Chao Phraya Chakri", which in itself is a combination of the word 'Chak' and 'Tri', thus denoting the two weapons.
This <i>W3C-unspecified</i> <a href="https://en.wikipedia.org/wiki/Vector_images" class="extiw" title="w:Vector images">vector image</a> was created with <a href="https://en.wikipedia.org/wiki/Inkscape" class="extiw" title="w:Inkscape">Inkscape</a> .
CC BY-SA 3.0
Own work by uploader, inspired by artwork created more than 200 years ago, based directly from:<a class="external autonumber" href="https://en.wikipedia.org/wiki/File:Chakrilogo.png">[1]</a> and <a href="//commons.wikimedia.org/wiki/File:Bkkchakrisymbgpalace.jpg" title="File:Bkkchakrisymbgpalace.jpg">File:Bkkchakrisymbgpalace.jpg</a>, the halo is from this picture:<a rel="nofollow" class="external autonumber" href="https://www.flickr.com/photos/10351444@N07/1111221645">[2]</a>. The Chakra is taken from the <a href="//commons.wikimedia.org/wiki/File:Flag_of_Thailand_(1782).svg" title="File:Flag of Thailand (1782).svg">File:Flag of Thailand (1782).svg</a> from Wiki Commons.