20 Baht - Rama IX Prime Ministers Office

Issued to mark the 120th anniversary of the Office of the Prime Minister, established in 1892 under King Chulalongkorn (Rama V) as part of his sweeping modernization of the Siamese administrative apparatus. The office was restructured significantly following the 1932 constitutional revolution that ended absolute monarchy, shifting its functional role considerably from its Chakri-era origins.