Thailand P136 50 baht 2018-2024 UNC king X311

20 Baht - Rama X (Series 17; paper) ND (2018)

Front: King Vajiralongkorn in Air Force uniform.

Back: Green on yellowish orange. King Rama I and King Rama II, Grand Palace, mural of a scene from Panji tales, Trishula trident in Chakra on guillochés.

The Thai state dates back to the Sukhothai kingdom in the 1200s, then the Ayutthaya kingdom in the 1300s-1700s. Modern Thailand begins with the Rattanakosin era founded in 1782, when the new capital was established at Bangkok and the Chakri dynasty commenced. The kings went from exercising absolute authority to constitutional rule after the 1932 revolution. The monarchy has acted as guardian of Buddhism, anchor of national symbolism, and patron of arts, architecture, and modernizing reforms across the 1800s and 1900s.

Kings of Thailand

• Rama I (Buddha Yodfa Chulalok) founded the Chakri dynasty, rebuilt Siam after Ayutthaya’s destruction, established Bangkok as the capital, began construction of the Grand Palace, and restored classical literature and Buddhist institutions.
• Rama II (Loetla Nabhalai) presided over a flourishing of poetry, court arts, and literary refinement during the early Bangkok period.
• Rama III (Nangklao) expanded trade with China, commissioned temples with Chinese architectural influence, and strengthened Siamese authority in Laos and Cambodia.
• Rama IV (Mongkut) modernized religion and statecraft, introduced Western astronomy, accurately predicted the 1868 solar eclipse, and promoted scientific engagement symbolized by the Khao Wang observatory and celestial imagery.
• Rama V (Chulalongkorn) abolished slavery, modernized the administration, built railways and postal systems, and traveled extensively in Europe, including the visit to Notodden, Norway, where he met industrialist Sam Eyde.
• Rama VI (Vajiravudh) advanced Thai nationalism, modern literature, and civic identity; he founded the Thai Boy Scouts in 1911 and cultivated a modern military image represented in mounted portraits.
• Rama X (Vajiralongkorn) appears on all Series 17 notes in Royal Thai Air Force uniform, reflecting his long military training and the contemporary ceremonial identity of the dynasty.

Chinese junk — emblem of thriving China–Siam maritime trade during the reign of Rama III and of the strong Chinese influence on Bangkok commerce and architecture.

Khao Wang observatory — Rama IV’s astronomical site in Phetchaburi used for eclipse calculation and evidence of the king’s integration of Western science.

Orion Constellation — reference to Rama IV’s scientific expertise and his internationally noted eclipse prediction.

• The eclipse occurred on 18 August 1868, visible as a total eclipse across the Gulf of Thailand and southern Siam.
• Rama IV calculated its timing and ideal viewing location using Western astronomical tables and geometry learned during his years as a monk, choosing Wakor, positioned exactly on the path of totality—exceptionally accurate for the era.  
• He invited European scientists and diplomats, including French and British teams, creating one of Southeast Asia’s earliest international scientific collaborations. Western astronomers praised his precision; Emmanuel Liais noted he possessed “the mind of a true European savant.”
• He used the eclipse to show that Buddhist cosmology could coexist with scientific cosmology, easing acceptance of modern knowledge in Siam. 
• The site was mosquito-infested; Rama IV and his son (Rama V) contracted malaria, and Rama IV died six weeks later—triumph and tragedy.
• The eclipse bolstered the monarchy’s reputation as rational, modern, and scientifically competent, strengthening Siam’s diplomatic standing with colonial powers. It embodied the Chakri dynasty’s strategy of selective modernization—adopting Western science and diplomacy without ceding sovereignty.
• Modern Thai astronomy commemorates the event; Wakor remains marked, and Rama IV is often honored as the “Father of Thai Science.” In 19th-century Thai astronomy, Orion’s Belt (ดาวไถ / Dao Thai, “the plough”) served as a key reference constellation, widely recognized and culturally embedded.

Panji mural — Thai adaptation of the Panji romance cycles originating in Java, integrated into Bangkok-era narrative painting. The Panji romances are Southeast Asia’s great indigenous love epic, born in medieval Java, later carried to places like Thailand, where their scenes were painted and carved in temples and palaces, including murals in Bangkok. Prince Panji and Princess Candra Kirana were betrothed from birth but are separated by intrigue and war, wander the world in disguise, meet again and again without recognizing each other, fall in love again under different names and identities, and are finally reunited. Indian and Buddhist tales center on gods, but these homegrown Southeast Asian epics focus on human emotion, loyalty, longing, and destiny—in fact, it's metaphysical: the soul forgets itself as it moves through changing forms, yet love carries an unconscious memory of unity and draws the separated halves back together. Existential. Panji shows up on temple reliefs, court dances, mask dramas, and murals from Java to Thailand — as a symbol of ideal kingship, faithful love, and the cosmic harmony when the divided finally becomes whole again.

The Thai currency (baht) evolved from the pre-modern silver tical system into a decimal baht under Rama V’s reforms. The modern baht is issued by the Bank of Thailand (founded 1942), with banknotes typically combining portraits of the reigning king with episodes from earlier reigns, state institutions, scientific achievements, and dynastic emblems such as the Trishula-in-Chakra.

The Thai alphabet developed in the 13th century from Old Khmer script. It is an abugida with 44 consonants and a tone system encoded through consonant classes, diacritics, and orthographic conventions that preserve historical sound patterns.

Thai cuisine’s international fame rests on its balanced sweet–salty–sour–spicy palate, the integration of Chinese techniques, refinement from Bangkok’s royal court, and strong regional diversity in Isan, Lanna, Central, and Southern traditions.