(เครื่องราชอิสริยาภรณ์อันมีเกียรติยศยิ่งมงกุฎไทย; RTGS: Khrueang Ratcha-itsariyaphon An Mi Kiattiyot Ying Mongkut Thai / Mongkut Siam). Instituted in 1869. Three-piece construction, in silver gilt with red and green enamels, measuring 48.2 mm (w) x 71.5 mm (h) inclusive of its tri-leaf suspension, chipping and loss evident in multiple red and green petals, on a length of original neck ribbon, fine. Footnote: The Most Noble Order of the Crown of Thailand (Mongkut Siam) was instituted on December 29, 1869 by King Mongkut Rama IV of The Kingdom of Siam (now Thailand) for Thais, the royal family, governmental employees, and foreign dignitaries, for their outstanding services to the Kingdom of Thailand. The order originally had seven classes and was awarded in five grades: Grand Cordon, Knight or Dame Grand Cross, Knight or Dame Commander, Commander, Companion and Member, plus a Gold Grade and Silver Grade medal. An eighth version, the Special Class, was added by King Rama VI in 1918.

