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In 989 after an upland chieftain, named Dương Tiến Lục, had reported to Lê Hoàn that local militia from the aboriginal prefectures of Ái Châu and Hoan Châuse planned to resist control by the Early Lê dynasty, the king authorised an attack on the prefectures.
References
Anh Thư Hà, Hò̂ng Đức Trà̂n A brief chronology of Vietnam's history 2000 Page 29 "Dưong Đình Nghệ (Diên Nghệ) (931-938) Dương Đình Nghệ was a native of Ái Châu. As a general of the Khúc family, he staged a rebellion resulting in the capture of the Đại La fortress (Hanoi nowadays)."
Nola Cooke, Tana Li, James Anderson The Tongking Gulf Through History 2011 p.95 "In the decade following the 982 attack on Champa, Lê Hoàn enfeoffed his sons with territory beyond the capital. In a series of campaigns to secure control of these territories, he and his sons came into armed conflict with the existing local leadership.22 In 989, for example, Lê Hoàn authorized a loyal upland chieftain, named Dương Tiến Lục in the sources to lead an attack on the aboriginal prefectures of Ái Châu and Hoan Châu because the chieftain had concluded that local militia from these prefectures planned to resist Lê control."