She was thrown into the Imjin River by Queen Dowager Myeongdeok after she complained of injustice and insisted that the king was her biological son.
[1] However, the veracity of these claims was questioned even in the Joseon period, and it is generally accepted that the boy, known by the childhood name Monino (모니노; 牟尼奴), was indeed King Gongmin's son.
[2][3] The Goryeosa records that King Gongmin banished Sin Don to Suwon in 1371, after which he named his son by Banya his heir.
The boy was renamed U and recorded to be the king's son by a deceased palace maid of the Han clan.
In 1376, Banya snuck into the residence of Queen Dowager Myeongdeok, where she complained, "I gave birth to the king, so how is it that his mother is of the Han clan?