In 1973, Thanom Kittikachorn's military government was facing several scandals, including corruption, and was heavily criticised for their lack of transparency. The criticisms resulted in a growing pro-democracy and anti-government sentiment, which transformed into a movement led by university students, organised under the National Student Center of Thailand (NSCT).
The government's final provocation to the protestors occurred on April 1973 with the Thung Yai hunting scandal, which highlighted the corruption among high-ranking government officers and enraged the nation.
Mass protest begun and the crowd reached its peak on 13 October at over 400,000 people. On 14 October 1973, while being ordered to disperse, violence broke out. The government brought in tanks, helicopters, and other military-grade weapons to support the police, resulting in 77 deaths and 857 injuries.
The next day, on 15 October 1973, the situation began to quiet down when it was announced that Prime Minister Thanom had resigned and fled the country along with Praphas Charusathien, Minister of Interior, and his son, Colonel Narong Kittikachorn.
On 6 October, Thirayuth Boonmee and ten other political activists were arrested for distributing leaflets in crowded places in Bangkok such as Bang Lamphu, Siam Square, and Pratunam, urging support for an early drafting of the constitution. The ruling government used a decree banning gatherings of more than five people to arrest them. The other arrestees were Thirayuth, Prapansak Kamolpetch, Boonsong Chalethorn, Bandhit Hengnilrat, Visa Kanthap, Thanya Chunkathatharn, Thawee Muenthikorn, Montri Juengsirinarak, Nopporn Suwanpanich, Preedi Boonsue, and Chaiwat Suravichai. They were taken to police headquarters and their homes were searched.
On 7 October, Kongkiat Kongka, accused of being a member of a group advocating early promulgation of the permanent constitution, was also arrested.
On 8 October, the twelve arrestees were denied bail and were also accused by Deputy Prime Minister Praphas Charusathien of being linked to a plot to overthrow the government.
On 9 October, more than 2,000 students from Thammasat University demonstrated at an anti-government rally. After the rally, the students held an all-night vigil, at which they were joined by students from Chulalongkorn University and several teacher training colleges. Khaisaeng Suksai, a former member of parliament, was also arrested, bringing the total number of those in custody to thirteen.
On 10 October, rallies in Bangkok swelled as more students from other student organizations joined the protests. The government prepared to react by quietly setting up a crisis control center with Praphas Charusathien as its director.
On 11 October, Praphas agreed to meet with the students, who demanded the release of the 13 prisoners. He refused to meet their demands. By this time, the rally had moved to the grounds of Thammasat University to accommodate its growing size, with the number of protesters now reaching 50,000.
On 12 October, the government announced that it would release the thirteen prisoners on bail, but the students rejected the offer, stating that they would only accept the unconditional release of the prisoners. Money was contributed by members of the public to support the protest.
On 13 October, the crowd, which had swelled to more than 400,000 (including many members of the public), marched to Democracy Monument to demand the release of the prisoners. The government quickly agreed to the demands and promised that the permanent constitution would be in place by October 1974. With their demands met, the students agreed to go back to their universities. About 200,000 students refused to disband, however, and their leader, Seksan Prasertkul, decided to lead them to the palace to seek advice from King Bhumibol (Rama IX).
On 14 October, the students reached the palace and were met by the king's representative, who said that King Bhumibol (Rama IX) requested that the students disband. The students agreed to do so, and the assistant director of the police ordered barricades placed to disperse the students in an orderly, single direction. The large size of the crowd meant that many were not able to leave, but the police refused their request for another exit, which resulted in resentment among the students. It is not clear how it happened, but reports soon were heard about violence against the students as the crowd became restive. Early in the morning, bombs exploded near the royal palace and the police began attacking the students.
By late morning, there were acts of vandalism and violence by both sides as the situation spun out of control. The government brought in tanks, helicopters, and infantrymen to support the police. Seventy-seven deaths and 857 injuries resulted and many buildings near Ratchadamnoen Avenue were set on fire. The number of demonstrators quickly grew to more than 500,000, as other students and their sympathizers rallied to their defense. The soldiers finally withdrew in the evening, and about 19:15 the king announced on television and radio that Thanom's military government had resigned.
Violence continued on 15 October around the police headquarters, with students demanding that Thanom be removed as head of the armed forces. Only when it was announced that Thanom, Praphas, and Thanom's son, Colonel Narong Kittikachorn, who was married to Praphas' daughter, had fled the country did calm return to Bangkok. The end had come as quickly and unexpectedly as the violence had begun.
