The French campaign against Korea of 1866 is also known as Byeong-in yangyo (Western disturbance of the byeong-in year).

It refers to the French invasion of Ganghwa Island in Korea in retaliation for the earlier execution by Korea's Joseon Dynasty of French Catholic priests proselytizing in that country.

The encounter, which lasts nearly six weeks, is the first armed encounter between Korea and a Western power.

The overall result is a French retreat.

The violent encounter also confirms Korea in its isolationism for another decade, until Japan forces it to end its isolationism in 1876 through the threat of military force.