Nam quốc sơn hà
Đại Việt sử ký toàn thư, Lament of the soldier's, The Tale of Kieu, Thuật hoài, Việt Điện U Linh Tập
Nam quốc sơn hà (Mountains and Rivers of the Southern Country) was a famous 10th century Vietnamese poem. Dubbed "Vietnam's first Declaration of Independence", it asserts the sovereignty of Vietnam's rulers over its lands. This poem was first dictated to be read aloud before and during battles to boost troops morale when Vietnam under Lý Thường Kiệt fought against the first invasion of Song dynasty in 981 though its exact authorship is still controversial.
Written in the form of an oracle, the poem is one of the best known Vietnamese literature pieces. It became an emblematic hymn in the early independence wars, recited by Lý Thường Kiệt on the Nhu Nguyet river defense line for the same morale boosting effect during the second Song invasion in 1076. In recent times, this same poem was often recited to show anti-Chinese sentiments by Vietnamese citizens when China began oil exploration in historically Vietnamese marine areas.