The flag of the Citadel of Nam Định (南定) flown during the Nguyễn Dynasty period.
File:Archive sur les symboles du Vietnam. Page 11.jpg. Note that the source page displays the characters in the wrong order, as historically Traditional Chinese characters (Hán script) was read left-to-right, this may be a misinterpretation on the part of the modern illustrators.
The imperial government of the Nguyễn Dynasty.