The release has coincided with the 28th anniversary of reunification and renewed soul-searching about German identity.
However, both families were unhappy with the final film and welcomed Herbig’s desire to, as he put it, “make a German film for an international audience”.
One of the most spectacular escapes from communist East Germany, in which two families sailed over the heavily fortified border in a homemade balloon, has been recreated as a thriller for the cinema.
Disney previously bought the rights to the story from both families and turned it into the 1982 film Night Crossing.