Unger was a German designer who moved to London in 1948 and there designed posters for the London Transport through 1974. In the mid-fifties this style, using painterly brush strokes emerged, making his work easily recognizable.
Hans Unger travel poster British United Airlines to Holland via vintageposterblog.com
Poster for the Tower of London
Travel in comfort c1955 via flickr
Whipsnade, 1956 via