The effect that Han Dynasty’s conquering of Korea had on the religion in the region was the introduction of Confucianism and Buddhism.
Confucianism originated from ancient China and the religion's belie was that human beings are good. The religion believes in justice and moral values.
Confucianism and Buddhism were both introduced by Han after Korea was conquered. Buddhism till today is still regarded as one of the main religion in Korea. Buddhism believes in change.
