O (surname)

O
Hangul	오
Hanja	吳
Revised Romanization	O
McCune–Reischauer	O

O or Oh is a romanization of a number of East Asian surnames.

O (Hangul: ) is the Korean form of the Chinese surname Wu (Hanja: ).

The name originates from the ancient state of Wu in present-day province of Jiangsu. Wu (吳, 오, "Oh" or "O" romanization) is the sixth name listed in the Song Dynasty classic Hundred Family Surnames.

In the 13th century BC, the state of Zhou (which will later become the Zhou Dynasty) was ruled by Tai Wang (King Tai of Zhou). His surname was originally Ji (姬). He had three sons: Taibo, Zhongyong, and Jili. King Tai of Zhou favored the youngest son, Jili to inherit the reins of power, therefore Taibo and his brother Zhongyong voluntarily left Zhou with a group of followers and headed southeast where they established the state of Wu. Taibo and Zhongyong's descendants eventually adopted Wu (吳) as their surname. The state of Wu, which later claimed to be a kingdom of its own, was best known for its military prowess as Sun Tzu, the author of the famed book The Art of War, was the country's general serving under King Helü of Wu. King Helu is considered to be one of the Five Hegemons of China during the Spring and Autumn period.

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