And there was reason for the rocking.

Our marriage would be a blow straight between the eyes of Chong Mong-ju.

He fought, with a show of strength for which Yunsan was ready.

Chong Mong-ju disaffected half the provincial priesthood, until they pilgrimaged in processions a mile long to the palace gates and frightened the Emperor into a panic.
But Yunsan held like a rock.

The other half of the provincial priesthood was his, with, in addition, all the priesthood of the great cities such as Keijo, Fusan, Songdo, Pyen-Yang, Chenampo, and Chemulpo.