Revanche first appeared in English in the mid-19th century, deriving, along with our noun "revenge," from the Middle French verb revenchier ("to revenge"). The word developed its specific political application in the years following the Franco-German War (1870-71), which resulted in France losing the territory known as Alsace-Lorraine to Germany. (The territory was returned to France following World War I and then twice switched hands again during World War II.) Although "revanche" appears occasionally in English today, you are more likely to encounter its relatives "revanchism," which refers to a government's policy of revanche, and "revanchist," referring to a follower of such a policy. These words did not appear in English until the 20th century.