Catholic Persecution of 1801
The Catholic Persecution of 1801, also known as the Sinyu Persecution (신유박해), was a mass persecution of Korean Catholics ordered by Queen Jeongsun during King Sunjo of Joseon's reign. The government began to suppress Catholicism in the belief that it conflicted with the tenets of Confucianism.
Source: Wikipedia — Catholic Persecution of 1801 (CC BY-SA 4.0)