His Majesty King Mongkut of Siam, Phra Bat Somdet Phra Paramendr Maha Mongkut, King Mongkut, the fourth monarch of the Chakri Dynasty of the Rattanakosin Kingdom, was originally named, as inscribed in the golden royal tablet, “Somdet Phra Chao Luk Ya Thoe Chao Fa Mongkut, Sommuti Thewawong Phong Itsarakan Kasattri Khatthiyaratchakuman.” He was the second royal son of King Phra Phutthaloetla Naphalai (Rama II) and Queen Sri Suriyendrabormarajini. He was born on Thursday, the fourteenth day of the waxing moon of the eleventh lunar month in the Year of the Rat, Chattasok, Chula Sakarat 1166, corresponding to 18 October 1804. At the age of twenty, he entered the monkhood and received the monastic name Vajirayan, meaning “one whose wisdom is strong like a diamond.” He remained in the monastic order for as long as twenty-six years. After King Nangklao (Rama III) passed away in 1851, members of the royal family and senior officials respectfully invited him to disrobe and ascend the throne on 4 April 1851, with the royal name “Phra Bat Somdet Phra Paramendr Maha Mongkut, King Mongkut.”

The reign of King Mongkut marked the first period of transformation toward modernization, involving social and cultural change to demonstrate that Siam was a civilized nation recognized by the international community. King Mongkut realized that Siam could no longer remain isolated as it had in the past, but needed to engage in trade with foreign countries and accept new Western ideas. Reforming and improving state administration in accordance with the international situation was essential, as was the modification of outdated customs. He adopted a middle path, combining Western and Eastern approaches, as reflected in his royal thought: “Do not cling to the old, do not be dazzled by the new; seek what is good in both the old and the new.”

Throughout the seventeen years of his reign, King Mongkut governed the country with great wisdom. He was both sovereign and a progressive leader, and among foreigners he was commonly referred to as “King Mongkut.” He was a monarch who upheld the Ten Royal Virtues, administered the kingdom, and carried out numerous royal duties that advanced the nation and brought great benefit to the country. These included the following.

He opened diplomatic relations with foreign countries. During his reign, Siam established friendly relations with nearly all major European and American nations. He ordered revisions to treaties of friendship and commerce, granting greater trade facilitation to foreigners than before. He abolished port duties, replacing them with import and export taxes, and permitted the export of rice. He adopted Western customs such as the handshake, first extending his hand to those granted an audience in 1866

And a practice that continues to this day. He abolished the requirement for foreigners to crawl in his presence, allowed them to stand in the throne hall, and permitted them to drink and smoke during audiences. He required Thai officials to wear shirts when attending royal audiences in accordance with Western civilized customs, and ordered royal residences and government offices to fly flags indicating their status, following the practice of foreign consulates.

Upon learning that European monarchs displayed insignia denoting royal honor on their attire, he ordered the creation of royal decorations and insignia representing the monarch. He coined the term “Dara” to translate the word “Star,” a term still used today to refer to components of royal decorations from the second class upward, including those with sashes.

He studied English with Dr. Caswell, Dr. Bradley, and Dr. House. In addition to English, he studied Latin with Bishop Pallegoix, as well as French, Pali, Sanskrit, and Mon. He was the first monarch of an Eastern country to possess knowledge of English, using it to study mathematics, astronomy, and other scientific disciplines. He also promoted English education among royal sons and daughters, and among princes and princesses of both the Inner and Outer Courts.

In politics and administration, he abolished the custom requiring people to close doors and windows when the king passed by, and the prohibition against looking at the monarch. He allowed commoners to approach him along royal processional routes, and set specific times for the people to present petitions directly to him. He introduced a system of selecting senior judicial officials by nomination rather than direct appointment, and ordered the publication of the Royal Gazette to disseminate official announcements and decrees in printed form for those concerned with government affairs.

He encouraged farmers to cultivate rice according to prescribed seasonal schedules, thereby promoting agriculture. He warned the populace to exercise caution in legal transactions requiring signed contracts, such as deeds of slavery, sales, and mortgages of land. He issued proclamations concerning slavery, requiring masters to accept redemption payments from slaves seeking freedom. He promulgated laws on personal and marital property, and enacted the Abduction Act, considered the first Thai legal document upholding women’s rights. He allowed women of the Inner Court to resign and marry outside the palace, except for royal consorts who had borne royal children. He reduced absolute royal prerogatives by rejecting the notion that the monarch alone owned all land in the kingdom, and promulgated laws regulating land prices. He was the first Thai monarch to take the oath of allegiance, vowing to perform royal duties for the benefit of the people.

In religious affairs, while in the monkhood he established a new monastic order known as the Dhammayutika Nikaya, emphasizing strict adherence to the Vinaya. This order aimed to reform Buddhism and restore proper monastic practice. He reformed preaching and religious instruction, introduced Thai-language chants, designated Makha Bucha as an important Buddhist holy day, corrected the Kathina robe ceremony to conform to the Vinaya, revised ordination procedures, and standardized monastic dress in accordance with disciplinary rules. He recognized the importance of broader education for monks and allowed them to study English with Dr. Caswell, a practice that has continued to the present.

He ordered the construction of roads in Bangkok and provincial areas to facilitate travel and transport of goods, including Charoen Krung Road, Bamrung Mueang Road, Fueang Nakhon Road, and Rama IV Road. He also ordered the excavation of canals to improve transportation and promote trade.

With increasing foreign trade, currency exchange became essential. As bullet money was insufficient, he ordered the replacement of bullet money with machine-minted coins and established the first royal mint in Thailand. In military affairs, he ordered the training of troops in European styles and the construction of sailing ships and steamships for naval defense and patrol.

During this period, various permanent structures were constructed, notable for their distinctive beauty, as they represented architecture that blended Western and Eastern styles. In the field of painting, King Mongkut graciously ordered the creation of mural paintings in ordination halls and viharns. A significant artist of his reign was Khrua In Khong, who pioneered Western-style painting and three-dimensional perspective. In sculpture, the King graciously ordered the casting of Buddha images and the replication of Buddha images to be bestowed upon monasteries. Literature of the period also flourished, as the King was a scholar and composed numerous works, both secular and religious. His dramatic work Ramakien, the episode Phra Ram Duen Dong, was written as an inner-court drama and demonstrates his mastery of poetic composition.

Another field in which the King was highly knowledgeable and skilled was astrology. He was renowned for the accuracy of his astrological predictions, which were considered unsurpassed. Examples include royal verses bestowed upon his royal sons and daughters. He also composed the Treatise on the Three Worlds, used for astrological prediction, which has been adopted as a principal reference by royal astrologers and practitioners of astrology up to the present day.

The wisdom of King Mongkut reflected his broad and profound knowledge in many fields, including modern science of his time. He showed great interest in science, particularly astronomy, and was honored by the Thai scientific community as the Father of Thai Science. It is said that he was especially interested in comets and proclaimed that his subjects should not believe rumors, but should understand such events as natural phenomena. He accurately calculated that a solar eclipse would occur on 18 August 1868, which took place exactly as he had predicted.

King Mongkut fell ill while returning from observing the solar eclipse, his condition worsened, and he passed away on Thursday, the 15th day of the waxing moon of the 11th lunar month, corresponding to 1 October 1868, having reigned for 17 years.