When she became queen, her husband already appointed Prince Gwanghae as an heir. Gwanghae was second son of Seonjo, born to Kim Gongbin, senior 1st rank the King's concubine. Gwanghae acted as the de facto ruler of the Joseon Dynasty during Japanese invasions of Korea in 1592 until 1598. In other hand, Seonjo's first queen consort, Queen Uiin, died without issue.