Co Mat Vien- The "CIA'' of Nguyen Dynasty

Origin and Purpose

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The "Le Van Khoi" Incident

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Lê Văn Khôi was the adopted son of Lê Văn Duyệt—a loyal and highly esteemed official under Emperor Gia Long, who was also the biological father of Emperor Minh Mạng himself. Lê Văn Duyệt was an exceptionally revered mandarin who was granted two extraordinary imperial privileges: “entering the court without bowing” (nhập triều bất bái) and “executing before reporting” (tiền trảm hậu tấu). These were highly exceptional honors, rarely granted in the entire history of Vietnam’s feudal dynasties.

Although Lê Văn Duyệt was a loyal official to the emperor-father (Gia Long), he harbored personal animosity toward the emperor-son (Minh Mạng) due to deep ideological differences. Lê Văn Duyệt had even expressed his opposition to Minh Mạng’s succession directly to Emperor Gia Long. Throughout his reign, Minh Mạng repeatedly sought to remove Lê Văn Duyệt from power, but was ultimately unsuccessful because of the immense authority and trust Duyệt had earned from the late emperor.

In 1832, shortly after Lê Văn Duyệt’s death (before that,he had been appointed Governor-General of the South since 1820 to oversee its development) Minh Mạng secretly instructed his close aide, Bạch Xuân Nguyên, to fabricate a case against him. Upon arriving in the South, Bạch Xuân Nguyên compiled an extensive, multi-volume report that listed accusations, gathered supposed evidence, and ultimately charged Lê Văn Duyệt with numerous offenses, including corruption and abuse of power.

In reality, Lê Văn Duyệt had greatly contributed to the development of the southern region. He was responsible for major infrastructure projects such as the construction of the Vĩnh Tế Canal (An Giang and Kieng Giang nowadays for the people, and had successfully suppressed invasions and uprisings from Chân Lạp (modern-day Cambodia). While he was beloved by the people, from the perspective of the royal court, his overwhelming power and open discord with the reigning emperor did constitute acts of overreach.

As a consequence, many of Lê Văn Duyệt’s relatives and associates were punished—some even executed. These actions triggered the uprising of his adopted son, Lê Văn Khôi, who had previously shown rebellious tendencies toward the imperial court. Khôi’s rebellion caused significant chaos, forcing the Nguyễn Dynasty to deploy numerous military forces to the South to restore order.

Interestingly, the bond between Lê Văn Duyệt and his adopted son began under unusual circumstances. In 1819, Lê Văn Duyệt was dispatched by the court to the North to suppress a rebel group in Thanh Bình (modern-day Ninh Bình). Ironically, that rebel group was led by none other than Lê Văn Khôi himself. Moved by mutual respect during the confrontation, Duyệt spared Khôi’s life. From that moment, Lê Văn Khôi pledged loyalty to Lê Văn Duyệt, eventually becoming his adopted son and close aide.

Today, Le Van Duyet's private residence—bestowed upon him by Emperor Gia Long himself—still exists in its original form and is located at 20 Phú Mộng Street, right at the entrance to the alley leading to Ancient Hue.

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After the Lê Văn Khôi uprising in the Southern provinces, Emperor Minh Mạng recognized the urgent need for a specialized agency in intelligence and national security. As a result, the Cơ Mật Institute (with the term ‘Cơ Mật’ translating to ‘top secret’) was established with the function of collecting, analyzing, and providing strategic information to safeguard the royal court and the country.

This agency was headed by four high-ranking ministers, each holding a rank of Chánh Tam Phẩm (Third Rank or higher), equivalent to the most important officials in the imperial court. They represented four key departments: Văn Minh Palace, Võ Hiển Palace, Cần Chánh Palace, and Đông Các Pavilion – central institutions responsible for civil administration, military affairs, policy planning, and scholarship under the Nguyễn Dynasty. The Cơ Mật Institute functioned as a "special inner cabinet" of the emperor.

Within the compound of the Cơ Mật Institute, in addition to the main building where the high-ranking officials worked, there were also two side wings. The right wing once served as the office of French delegates (Délégué), while the left wing was used as an Economic Museum (Musée Économique).

Although the architecture has remained largely unchanged, the function of this historical site has evolved over time. From 1955 to 1975, under the former regime, the two side buildings were used as offices for local judicial agencies (serving Thừa Thiên Province and Huế City), while the main building – the Cơ Mật Institute – became a courtroom for trials ranging from first-instance to appellate level.

Today, the site is located at 23 Tống Duy Tân Street, in Thuận Thành Ward, at the southeastern corner inside the Imperial City of Huế.

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