The Royal Siamese Armed Forces was the military arm of the Siamese monarchy from the 12th to the 19th centuries. It refers to the military forces of the Sukhothai Kingdom, the Ayutthaya Kingdom, the Thonburi Kingdom and the early Rattanakosin Kingdom in chronological order. The Siamese army was one of the dominant armed forces in Southeast Asia. As Thailand has never been colonized by a European power, the Royal Thai Armed Forces boasts one of the longest and uninterrupted military traditions in Asia. The army was organized into a small standing army of a few thousand, which defended the capital and the palace, and a much larger conscription-based wartime army. Conscription was based on the "ahmudan" system, which required local chiefs to supply, in times of war, a predetermined quota of men from their jurisdiction on the basis of population. The wartime army also consisted of elephantry, cavalry, artillery, and naval units. In 1852, the Royal Siamese Armed Forces came into existence as permanent force at the behest of King Mongkut, who needed a European trained military force to thwart any Western threat and any attempts at colonialisation. By 1887, during the next reign of King Chulalongkorn, a permanent military command in the Kalahom Department was established. The office of Kalahom, as a permanent office of war department, was established by King Borommatrailokkanat (1431–1488) in the mid-15th century during the Ayutthaya Kingdom. Siam's history of organized warfare is thus one of Asia's longest and 

uninterrupted military traditions. The Royal Thai Armed Forces were involved in many conflicts throughout its history, including global, regional and internal conflicts. With the rapid expansion of the French Empire into Indochina, conflicts necessarily occurred. War became inevitable when a French mission led by Auguste Pavie to King Chulalongkorn to try to bring Laos under French rule ended in failure. The French colonialists invaded Siam from the northeast and sent two warships to fight their way past the river forts and train their guns on the Grand Palace in Bangkok (the Paknam Incident). The French also declared a blockade around Bangkok, which almost brought them into conflict with the United Kingdom. Siam was forced to accept the French ultimatum and surrendered Laos to France, also allowing French troops to occupy the Thai province of Chantaburi for several decades. The first Royal Guards unit was established by King Chulalongkorn (Rama V) in 1859, when he was still the heir. Initially, the Royal Guards were servants with duties such as scaring crows, which led to commoners referring to them as the "Mahat Lek Lai Ka," roughly translated as "Scarecrow Corps". When he succeeded his father in 1868, King Chulalongkorn took his Royal Guard and formed a 24-strong Royal Bodyguard, referred to as the "Thahan Song Lo" (Two-Dozen soldiers"). In 1870, the Royal Guard regiment were given the name the "King's Guard" and their duties included escorting the king while he travelled around the country. About the year 1875 the necessity for surveys in connection with improvements in the city of Bangkok, and for supervision in carrying out these improvements, led to the selection of certain officers of the royal bodyguard for training in this direction. These officers were formed into a special company called "Military Engineers of the Royal Bodyguard," in which Mr. James McCarthy held the rank of captain. A royal decree issued September 3, 1885, separated the surveyors from the royal bodyguard and created the Royal Survey Department, which is now the Royal Thai Survey Department, a Special Services Group of the Royal Thai Armed Forces Headquarters. The Royal Guards still exist down to the present and many more units from all branches of the armed forces were given this distinction.