Srei Soriyoapor ស្រីសុរិយោពណ៌
King of Cambodia
Reign	1602 – 1618
Coronation	1602
Predecessor	Preah Keo Fva I
Successor	Chey Chettha II
Born	Longvek, Cambodia
Died	1620 Oudong
Issue	Chey Chettha II Outey Reachea
Names Preah Reach Angkar Preah Borom Reachea Thireach Preah Srei Soriyoapor
House	List of monarchs of Cambodia
Father	Borom Reachea II
Religion	Buddhism Theravada

Borom Reachea IV or Srei Soriyoapor (Khmer: បរមរាជាទី៤), ឬ (Khmer: ស្រីសុរិយោពណ៌) (Siam-call: Srei Soriyopear) was the Cambodian king ruled from 1602 to 1618. After the official coronation ceremony in Lavea Em in 2147 BE, 1603 AD, Maha Sakarach 1526, His full name was called "Preah Reach Angkar Preah Borom Reachea Thireach Preah Srei Soriyoapor", which means "Priya Raja Nagar Priya Brahma Raja dhi Raja Priya Shri Suryaputra" in Sanskrit, Prakriti and Pali language, which has been distorted by the misunderstanding of some modern day scholars. He was the second son of the Borom Reachea II whose original name was Brahma Raja II and was the younger brother of Preah Satha I, who was captured by the Siamese king and sent to Ayutthaya which is similar to word Ayodhya, during the Siamese army's attack on Longvek city in 1593 AD.^[1]

After Soriyoapor staged a coup to seize the throne from Preah Keo Fva I in 1602 AD, He moved the capital from Slaket Island to establish a new capital in Lvea Em in 1603 AD. During the proclamation of Soriyoapor as King of Cambodia, he issued a letter requesting his two sons from Siam King, who had been held hostage in Ayutthaya, to return to Cambodia to inherit the throne. He sent some tribute to the Siamese mayor and promised to practice Buddhism in the form of Theravada Buddhism. Naresuan king of Ayutthaya was very upset, but he agreed to Srei Soriyoapor's request, but he kept his eldest son, Chey Chestha, to stay in Ayutthaya, and he sent his second son, Outey Reachea, the youngest son, Let him return to the Kingdom of Cambodia. After Soriyoapor defeated Preah Keo Fva I, but the country has not yet achieved national unity, because many district governors have formed rebel factions and former monarchs, and And they all have their own ambitions to divide Cambodia to rule their respective regions in this way, and that's why Soriyoapor sent two strong generals, Techo Meas and Techo Yot, out to defeat them, All these rebellions. Starting to attack the Baray district chief of Asantuk province (now: Kampong Thom), then to suppress the insurgents in Kork Ses province (present: Banteay Meanchey) and continue to suppress the insurgents in Kampong Siem and Stung Trang districts of Kampong Cham province, Cheung Prey District (Current: Tbong Khmum Province).^[2]

The last insurgency in Thmor Koul district, Battambang province, ruled by King Utey Thireach, who was not his real name, his real name was Ponhea Nou, the third son of Borom Reachea II, He was a half-brother with Soriyoapor, but different mother. During the Siamese siege of Longvek 1593, he hid and changed his name so that the Siamese army could not find him. Srei Soriyoapor knew that Utey Thireach was his brother, Ponhea Nou, so he ordered the army chief named Techo Meas to capture Utey Thireach alive by ordering him to be called preah Ream Thmor Koul. Eventually, Utey Thireach was captured and brought to the King, Ponhea Nou, unaware that Srei Soriyoapor was the current king, because he thought he had died in the Longvek battle. With joy and remembrance, Srei Soriyoapor did not punish Ponhea Nou, but appointed Ponhea Nou as the district governor of Samrong Tong province (now: Kampong Speu province) in 1604 AD.^[3]

Srei Soriyoapor, the royal name call Borom Reachea IV, reunited Cambodia during a five-year war to crush the rebels, beginning from 1601 to 1605 AD. Only then did he completely suppress the rebels throughout the kingdom. Soriyoapor restored Cambodia through the establishment of a local administrative system and the promotion of religion, allowing for the spread of other religions, as well as Buddhism. It is the state religion, respecting the forms of Theravada Buddhism under the influence of the Siamese mayor. In 1618, in order to turn away from Siamese influence, he sought to forge allies and the kingdom of Annam to use relations with Annam to free itself from Siamese oppression. So he sent an envoy to the Emperor of Annam, at Huế city, The Annam king named Sai Vuong, to propose to his second daughter, Sai Ngọc Vạn, to marry with his son Chey Chestha II (Siam-call: Chey Chettha). The Annamite emperor agreed to the request and arranged for his daughters to be sent on 15 ships with 500 maids and 500 male servants. The coronation took place in Lvea Em, with Annam's daughter being required to change her name to "Ang Zhou" to make it easier to identify her name in Khmer. This alliance displeased the Siamese mayor and raised a large number of troops to invade Cambodia after the death of the Cambodia king Borom Reachea IV or Srei Soriyoapor in 1620 AD.^[4][5]