Exactly just such a person was Hermine Gallia, who was painted by Klimt in 1904. (See page 47.) She is shown dressed in a ruffled and layered white dress designed by the artist and set against a pale pastel backdrop blocked in with feathered strokes. The only darkness in the portrait is in her hair, eyebrows and eyes. The artist wrote: "Whoever wants to know something about me ought to look carefully at my pictures and try and see in them what I am." The same is true of the people he portrayed. Hermine here is not an aristocrat by birth but by taste. She appeared in a family photograph a decade later in the same head-tilting pose "trying to live up to Klimt's picture". 

The exhibition traces the origins of Viennese portraiture back to the Biedermeier period of the early 19th century. The informal domestic portraits by artists such as Friedrich von Amerling and Ferdinand Georg Waldmüller were "rediscovered" by the city's later painters. It was a style that could serve both painterly tradition and modernity, and represent both social security and personal anxiety. Some artists, such as Alois Delug, merely updated the tradition in their portraits, while others, such as Klimt, Oskar Kokoschka and Egon Schiele, developed Biedermeier immediacy and formal simplicity in ways more compatible with the contemporary age. The defining characteristic of this new Biedermeier is a sense of introspection.

Schiele, one of art's greatest portraitists — or at least depicters of the individual  — was perhaps the most distinctively Freudian artist in Vienna. A painting such as The Family (Self portrait) of 1918 reworks a long- established genre in an unnerving new way. It shows the painter with a woman and a child. She is not, though, his wife Edith but a female model and the child is not his but a projection: Edith had just been confirmed as pregnant when the picture was started. The woman sits between Schiele's legs, the child between hers, both father and "mother" are naked. The grouping forms a knot of flesh tones and for all the intimacy of the scene the figures don't react to one another. They are together but alone and their nakedness is not erotic but psychological as well as physical. Schiele and the woman are Adam and Eve post-Fall. If the painting deals in part with sex, it also has associations with death. Schiele died shortly after the portrait was completed, in the Spanish flu epidemic that followed the end of the war, just three weeks after the death of his wife; their unborn child died with her.

Schiele's peers did not hesitate to use strangeness and modernity in their portraits too. Unfamiliar names such as Anton Romako, Max Oppenheimer and Richard Gerstl, as well    as women artists such as Broncia Koller-Pinell and Elena Luksch-Makowsky, pushed the acceptance of their patrons to its limits. Romako's portrait of Isabella Reisser, for example, remains deeply uncomfortable. She was the wife of the technical director of a leading liberal newspaper but, despite the fact that Romako showed her as a cinched-waisted woman of fashion she is also a beige and ghostly figure with a death's-head rictus. Isabella is a woman ill at ease in her painterly space, a reflection perhaps of her role in society.

What this exhibition presents is a composite portrait of a city through its citizens. In Freud's words: "The ego represents what we call reason and sanity, in contrast to the id which contains the passions." Vienna's portraitists found both in plentiful supply.