Agatha Sadler: Refugee from the Nazis who became a much admired bookseller and art collector

She made book-buying fun - customers could be sure of a warm welcome from morning until late evening

With the death of Agatha Sadler, London has lost a great bookseller and dedicated art collector with a genius for friendship. She certainly earned her success.

She was brought up in a cultivated and wealthy Jewish Austrian family, but her privileged childhood came to an end after the Anschluss of 1938 when, at the age of 14, she arrived almost penniless in Croydon and, after a brief period at school there, worked in a factory. Petite, trim, vivacious and clever, she dreamed of becoming an actress, but her Viennese accent proved too much of a casting handicap for a career in the British theatre. But as a bookseller, she turned her typically Viennese femininity to advantage, and she never lost her looks, sociability and appetite for the good things of life.

Her art book business, the St George's Gallery, began in 1945 in a room at 81 Grosvenor Street, where her father, an atomic physicist-turned-leather goods manufacturer, started dealing in drawings by modern masters. Money was so short that if she wanted to post a letter she could only pay for the stamp by selling a book, and this taught her to be cautious.

Young and pretty, determined to learn, she won the admiration of a wide range of experts – the critic Denys Sutton, the Old Master drawings specialists Hans Calmann and Albert Scharf and the modern art collector Eric Estorick – who advised her on what books to buy and what to avoid. After 1950, when her father gave up, she moved to a succession of premises until finally, in 1964, to her shop in Duke Street.

Her timing was perfect, for London was emerging as the world centre for the art market. This was the result of two world wars and high taxation, when many country houses were destroyed and their contents dispersed. The quantity of works of art thus made available not only led to the expansion of the sale rooms but to the colonisation of whole areas of London by groups of dealers.

These streets, which had an attractive atmosphere, were busy with museum curators, foreign dealers and collectors with varying amounts of leisure and money to spend, all looking to see if “something interesting” had come in. As a consequence of this activity, there arose a demand for scholarly publications and for antiquarian reference books which the St George's Gallery was ideally placed to supply.

It was situated between the two leading auction houses, Christie's and Sotheby's, and few of the cognoscenti, English and foreign, on their way from one to the other failed to call in to buy the latest art books and the exhibition catalogues which were Agatha's speciality. More than that, she made book-buying fun. As in a club, customers could be sure of a warm welcome because, seated at the front of the shop every day from morning until late evening, she was ready to entertain them with cups of coffee, a glass of wine and gossip.

For her staff, Sadler's intense enjoyment of every aspect of the business, from her friendships with customers to the excitement of unpacking the constant flow of consignments of new books, generated an exceptionally happy working atmosphere. Since her only rivals, Zwemmer and CG Rosenberg, were not so centrally located, with her experience, expertise and personality she soon rose to prominence.

Besides her private clientele, she impressed the Getty Museum, the Courtauld Institute, the Victoria & Albert Museum , the National and Tate Galleries, and also commercial firms – Sotheby's, Christie's, Colnaghi and Matthiessen – who commissioned her to bring their libraries up to date. A talent-spotter, she encouraged the young Pat Wengraf and Robin Symes to deal respectively in sculpture and classical antiquities. The latter, at the peak of his success, held a great celebration to honour her 70th birthday because, he said, he “owed everything to her”.

In the background was Charles, a fellow drama student whom she married in 1944, and whose practical support underpinned the success of the Gallery. They were young and poor – their honeymoon was a walk in Richmond Park and their first home a one-room flat in Camden Town.

After the business made money, they moved on to a fine house in Kensington Gate, which from 1954-1992 they filled with works of art acquired from close friends: Greek and Roman antiquities from John Hewett, Renaissance bronze statuettes, still life and Barbizon School paintings from Jack Baer of Hazlitt, Gooden and Fox. For Agatha and Charles, art was to be lived with, and not gazed at through glass cases within a museum.

This was particularly true of her choice collection of classical gold jewellery, which she wore to great effect, arrayed like a Hellenistic queen, surrounded by admirers at her dinner parties. Since, after selling books she enjoyed nothing more than cooking, the food was superb and the irrepressible Brian Sewell, a great favourite, kept the company entertained.

During the long period of retirement from 1989 (when she sold the St George's Gallery to a specialist in books on Oriental art), these friendships, her sense of hospitality, her love of good conversation, music and the arts remained with her, and she kept her joie de vivre until the end.

Agatha Brill, bookseller and art collector: born Vienna 24 January 1924; married Charles Sadler (died 2003); died 13 December 2015.