Family name Герген (Gergen 
, Герген 
, Gergena 
) , in all the world, is quite a rare last name. The last name Герген is characteristic of Luxembourg, where it is quite a rare surname, Hungary, where it is a rare surname, and Germany. Not in comparison with a country's population, it is commonest in the United States, Germany, and Turkey. Very seldom, Герген is the forename as well as the last name.