Ngiao rebellion
The Ngiao rebellion (), also called the Phrae City Rebellion and the Shan rebellion, was an uprising of Tai Yai (Shan, historically known in Thai as Ngiao) people against Siamese rule, in what is now Phrae province in northern Thailand between 25 July and 14 August in 1902. It arose as resistance to centralizing reforms initiated by King Chulalongkorn, particularly the levying of taxes and the adoption of the Monthon Thesaphiban provincial administration system, as well as the partitioning of territory with the British, which forced the Shan to adopt either British or Siamese nationality. In the morning of 25 July 1902, rebels attacked and looted the town of Phrae, killing over twenty government officials including the royal commissioner, Phraya Ratcharitthanon. The rebellion was soon quelled by troops from Bangkok led by Chaophraya Surasakmontri, as well as Siamese troops commanded by British and Danish officials. Ten rebel leaders were executed, sixteen were took to Bangkok for imprisonment, and , the ruler of Phrae, escaped into exile in Luang Phrabang. The rebellion continued onward as an insurgency until May 1904 and spanned across Northern Siam. The revolt was part of several acts of resistance that arose in the fringes of the country in the 1890s to early 1900s. A few months earlier, the Holy Man's Rebellion in the Northeast saw rebels sack the town of Khemmarat before being routed by the Siamese army. While it was unclear whether and to what extent the local rulers supported the rebellion in Phrae, the local lordship of Phrae was ended, and further reforms were put into place that helped Siam fully annex the former lands of Lanna and assimilate its people. History

Background 
During the reign of King Chulalongkorn (Rama V) and his predecessor, Siam had loss numerous territories to France and Britain, normally lands ethnically non-Thai. In 1885, Siam was forced to cede its northern Shan provinces, which partitioned the Shan people between British and Siamese rule. In order to tighten and retain the land left, King Chulalongkorn began passing reforms which centralized the country around Bangkok and reduce the power of local rulers, with local rulers in the country's north being forced to hand over higher taxes and most of their power. On 10 October 1899, a previous revolt occurred in Chiang Mai against increased taxes. The revolt was led by Phya Pap and aimed to install him as king and expel all Siamese and Chinese people from the area. The revolt was poorly organized and collapsed quickly. In Muang Prae, Phraya Chaiboon (Thongyuu Suwanbat) was appointed as governor in 1897. The previous leader Chao Phiriya Thepphawong had previously ruled Phrae as the local king under Siamese vassalization similar to Kingdom of Chiang Mai and other northern states. Tensions before the rebellion 
In early July 1902, Siamese police attempted to arrest a group of Shans in a ruby mine in Baan Baw Kao, south of Phrae town, without consulting the head of the mine, Sala Po Chai. The Shans resisted and fighting broke out with the police, resulting in the death of several policemen. The police retreated from the mine and assembled a force of 80 police and soldiers equipped with horses and elephants. They then began advancing back towards the mine on 23 July but were ambushed by the Shans in a ravine which led to the mine. The ambush destroyed the Siamese who fled to Lampang. Here, the Shan killed 16 Siamese and took possession of the Siamese equipment which included horses, elephants, guns and ammunition. Knowing that they would face retaliation from the Siamese in the future, the Shans led by Sala Po Chai and Phaka Mong set out on a rebellion. Early days 
On 25 July, 50 Ngiao rioters stormed the local police station in Phrae and due to the small amount of officers inside, easily took over the station and seized weapons, killing numerous policemen. Despite warnings, Phraya Chaiboon had not permitted the police to have ammunition, most likely as he did not trust the police as they were recruited locally. Afterwards, rioters destroyed telegraph lines and stormed the governor Phraya Chaiboon's residence. However, Chaiboon had already fled the town with his wife Lady Yean to seek help. With the governor gone, the rioters took the treasury's money totalling 46,910 Baht and killed the remaining servants in the building. They then went to the local prison to increase their numbers from 50 to 300. In the chaos, many villagers fled Phrae, although the rioters told the town folk that they would not be harmed but instead the Siamese who ruled over them. Their numbers soon increased with local villagers joining their cause. The leaders, Slapochai and Phaka Mong, travelled to Khum Chao Luang where they convinced Phiriya Thepphawong there to join their cause and to also provide food and weapons. The rebels also presented their case to British officials in the town who were employed by the Siamese Forestry Department. The Shans were led by Phaka Mong. On 26 July, the Ngiao began hunting ethnic Central Thais (Siamese), but also encouraged their murder through prizes totalling 400 Baht per person, including women and children. Three days after fleeing Phrae, Chaiboon went to local villagers in Ban Rong Kat to beg for food. In hopes of taking a prize, one of the villagers reported Chaiboon to the rioters and he was later arrested. Once back in Phrae, the Shan began forcing him to give up Phrae to the Shan, although he never signed. Chaiboon was later killed by one of the rioters, Jeong Shen, after challenging them to kill him. The site of Chaiboon's death is now a monument and Chaiboon was later promoted to Phraya Ratcharittanon Paholpolpakdee. Along with Chaiboon, numerous Siamese officials were murdered. However the former treasurer of the Phrae, Phra Wichai Racha, hid three Siamese government officials from being murdered by rioters. In addition to the local residents, Westerners were unharmed such as Dr. Thomas who led an American Presbyterian mission in Phrae. In total, 20 Siamese officials were murdered, making it the largest massacre of Central Thai officials in Northern Thailand. Battle of Lampang 

Upon learning of the situation in Phrae, King Chulalongkorn assigned Chao Phraya Surasak Montri to lead Siamese forces from Bangkok to suppress the rebellion whilst local troops from nearby towns were called in to assist. Upon learning that Surasak Montri was heading north, the Shan split their army into two divisions - with Salapochai leading the men in the south whilst Phaka Mong lead troops to attack Lampang. Bolden by their success in Phrae, Phaka Mong and Sala Po Chai drew up plans for the liberation of Northern Thailand, planning to continue on to Chiang Mai, Lamphun, Phayao and Chiang Saen after a victory at Lampang. News of a Shan attack on Lampang came from Nai Fuang, a judge from Phrae, who escaped and telegraphed this information of 26 July. The King of Lampang, Bunwatwongse Manit began preparing his town's defences by assembling a force of 1,000 irregulars. To prevent Lampang's prisoners from joining the rebels like the prisoners in Phrae did, all the prisoners were executed. From Chiang Mai, 54 policemen were sent to Lampang under the command of Danish captain Hans Markvard Jensen. Jensen had arrived in Siam as a police trainer from Denmark. They arrived on 29 July. At the same time Lampang at been substantially fortified, with nine v-shaped teak barricades erected under the orders of British teak company officials blocked major roads into the town. Most of the town's defenses had been coordinated by Louis Leonowens, son of Anna Leonowens. On 3 August, Phaka Mong forces arrived at Lampang and began attacking the town on 4 August during dawn with 200 men. His forces advanced towards Chao Bunwatwongse's residence along Bunwat road and while another was beside the Wang river. The Shans along the river seized the barricades there  but the forces along Bunwat road failed to take barricades held by Captain Jensen and Lt Tjoen. Jensen then led his forces to fire upon the Shans along the riverside. Along the riverside, the Shan came under constant fire including from Leonowen who was firing from the Chao's residence where he was protecting the Chao and the Siamese Commissioner. The Shans began fleeing from Lampang before being followed behind by Lampang's forces who were promised 300 Baht for each Shan soldier. This counteroffensive would end up killing at least 25 Shans, including Phaka Mong. Together, their heads were displayed in front of the Chao's residence on sticks. Despite Phaka Mong's failed offensive, officials in Chiang Mai and Lampang were still unsure on whether the Shans would launch further attacks. In Chiang Mai, the city gates were barricaded and 5,000 soldiers were recruited in the city's defences. Under Jensen and Leonowen, the Chao of Lampang was evacuated to Chiang Mai. This however caused Lampang to fall into anarchy for three days with widespread killing and looting as they were without any rulers. On 7 August, Bunwatwongse returned to Lampang and restored order. For Captain Jensen's role in defending Lampang, Chulalongkorn intended to promote Jensen to rank of Major General and bestow him with the Order of the Crown of Siam and 10,000 baht. However Jensen was later shot along with Lt Tjoen, by Shan rebels on 14 October 1902 at Muang Ngao after being abandoned by his men, apart from Tjoen. Chulalongkorn then presented Jensen's mother in Denmark 3,000 baht for her son's service. His final resting point is in Phayao, while an obelisk in a Chiang Mai cemetery is dedicated to him. Closing days 
On 5 August, the 24 year old British vice-consul based in Nan, Harold Lyle, was dispatched by British officials in Chiang Mai arrived into Phrae and moved into the former residence Phraya Chaiyabun in an attempt to restore order. Lyle began writing to Sala Po Chai urging him to not engage with Surasak Montri in battle. He also attempted to raise the moral of the foreign residences by organizing a game of polo. On 7 August, defeated Shans from the Battle of Lampang started returning to Phrae where Lyle encouraged them to disperse and flee to British Shan territories. However, Sala Po Chai did not follow Lyle's wishes and Lyle rode 8 km on 13 August to meet with recently arrived Siamese forces under the authority of the governor of Pichai, Srisuriyarajvaranuwat. There, he delayed the Siamese from entering Phrae by saying that Phrae had no rice to feed his men and that if they encountered a Shan army, they would be destroyed. This was due to his fears that it would result in a massacre of local and foreign residences for three days. During this, more Siamese soldiers arrived and were led by Danish commander-in-chief of the Siamese Provincial Military Police Gustav Schau. At the same time, Salapochai's forces in the south were defeated by armies from Sawankhalok and Sukhothai. On 16 August the governor of Pichai, Phraya Srisuriyarajvaranuwat, led provincial police and took over Phrae. Surasak Montri arrived in Phrae on 20 August. Immediate aftermath in Phrae 
With the death of Sala Po Chai and Phaka Mong, the Shan rebels mostly dispersed. Although 10 were executed in Phrae whilst 16 were captured and sent to Bangkok for a trial. Majority of these prisoners faced 9 months-2 years of imprisonment for their involvement in the Battle of Lampang. However, some were sentenced 15 and 12 years. After arriving on 20 August, Surasak Montri began investigating the rebellion's cause, coming to the conclusion to the support of the governor, Chao Piriya Thepwong, helped the rebellion grow. Before punishing the governor, Chao Ratchawong and his wife drank poison, committing suicide. Fearing that this would cause a misunderstanding and the Siamese government will be accuse of causing violence against the governor, Chaophraya Surasakmontri began spreading rumours that the ruler of Phrae will be arrested. Chao Piriya Thepwong would later escape Phrae with two close friends. He was however supported by Surasakmontri who gave secret orders to local troops around the city to not intercept him. Chao Piriya Thepwong would later escape to Luang Prabang, which was under French colonial rule. After 15 days, it was considered that he abandoned all of his duties and Surasakmontri ordered Chao Piriya Thepwong's removal from his position, making Piriya Thepwong the last king of Phrae. In his absence, he was charged with rebellion and sentenced to death. Piriya lived out the rest of his life in Luang Prabang until his death 10 years later in 1912. Guerilla war 
Following their defeat, some Shan rebels regrouped north of Phrae around Chiang Saen and Chiang Khong along the Lao side of the Mekong near the point where today Myanmar, Thailand and Laos's borders meet. They were however protected from Siamese military retribution as they were in a reserve zone in territory the French were interested in, which for the Siamese was demilitarized. The French were interested in pushing their control into the reserve zone and were sheltering the rebels in the hope that they would destabilize Siamese control. Throughout 1903, they led raids on northern towns including a failed raid on Chiang Rai. In early 1904, the local chief of Chiang Khong was replaced by a Shan rebel after Shan attacks became too much for the chief to handle. By May, Chiang Khong descended into a state of anarchy. The Siamese were however fed up with the Shan rebels. Surasak Montri destroyed Baan Baw Kao village where the rebellion originated. Surasak himself had faced insurgencies and rebels in the north before as a veteran of the Haw wars. Across the north, villages were destroyed by the Siamese if they had signs of rebel activity. Ta Pha affair 
Particularly one incident would affect Siam's relations with the British. 30 Shans and 100 Laotians seized Ta Pha and forced the villages to construct barricades. On 26 October 1902, hundreds of Siamese soldiers entered Ta Pha village in modern Phayao province. Ta Pha housed a Bombay Burmah Trading Corporation (BBTC) compound which was owned by the British. The rebels had erected several barricades along roads, but as the Siamese approached, the Shans fled. However, the Siamese still fired salvos onto Ta Pha and entered the BBTC compound and took down their company flag. At least five locals were killed along with several BBTC women. From the compound, one Burmese and one Shan who worked on the teak plantation were executed outside Ta Pha and the Siamese spent five days destroying the village. Harold Lyle was suspicious that British subjects did anything wrong and travelled to Ta Pha along with the French consul Lugan and Belgian lawyer Robyns. This would cause outrage from the British where they insisted on an investigation of the massacre. In late 1903, the commander of the Siamese forces at Ta Pha, Datsakorn, was sentenced to 12 years of imprisonment. End of the insurgency 
After receiving information in April 1904 about an upcoming attack on Chiang Rai, the Siamese requested French permission to enter the reserve zone. Previously in Bangkok, a treaty had been signed with the French which ceded the rest of Siam's control over Laos to the French. This treaty also eliminated the reserve zone as it came under French control. Now that the rebels were in French territory and were no use to the French, the colonial French administration also now wanted to eliminate the Shan rebels. The Governor-General of French Indochina approved the Siamese request and Siamese soldiers and artillery entered the reserve zone in the middle of May. They captured Chiang Khong easily from the Shan as they quickly retreated to the opposite side of the Mekong. However resistance in Chiang Saen led the Siamese having to make two attempts to capture the village which they captured. Effects 
After the rebellion, logging previously overseen by local rulers was handed over to Western companies such as the East Asiatic Company and the Bombay Burma Trading Corporation. This would cause economic growth in Phrae province, with many banks and businesses being set up to cater to the increasing logging trade and the increase in population. References

Further reading 

Rebellions in Thailand
1902 in Siam
Conflicts in 1902
Rama V period