Joseph Otto Flatter was born into a middle-class Jewish family in Vienna, Austria-Hungary (now Austria) in 1894 and trained at the Academy of Fine Arts Vienna. Arriving in London in 1934 with his pianist wife, Flatter is best known for his refined portraits and his anti-Nazi political cartoons. Following the outbreak of the Second World War, he was interned in 1940 as an 'enemy alien' in Hutchinson Camp, Douglas, on the Isle of Man; after his release later the same year, he was one of only two foreign artists granted drawing permits to make sketches of the Blitz and its aftermath.
Painter and caricaturist Joseph Otto Flatter was born into a middle-class Jewish family in Vienna, Austria-Hungary (now Austria) in 1894. His brother Richard Flatter (also an émigré to Britain), was a renowned scholar and translator of Shakespeare's works. Flatter trained at the Academy of Fine Arts Vienna; however, his studies were interrupted by the outbreak of the First World War, in which he served as a private and then as an officer in the Austro-Hungarian Army in South Tyrol, Italy. Financial difficulties after the war prevented him from completing his studies, and he worked as a portrait painter, travelling in Eastern Europe, and as a lecturer in Brno, Czechoslovakia in 1934. Shortly afterwards, he married Hilde Loewe (Hilda Löwi), an accomplished pianist-composer, and together they immigrated to Britain later in the year. Strictly speaking, Flatter was not a refugee, since his wife had prior engagements in the UK and the couple decided to remain because they liked the culture (Vinzent 2006, p. 153). They settled at 32, Elm Tree Road, St John's Wood, London NW8, close to Finchley Road, sometimes referred to by locals as 'Finchleystrasse', owing to the significant number of German-speaking refugees who settled there from the mid-1930s onwards. Flatter continued to work as a portraitist, executing commissions for the Austrian ambassador, Sir George Frankenstein; first Director of the London School of Oriental Studies, Sir Denison Ross; and the actor Emlyn Williams, among others.
Flatter is best-known, however, for his Mein Kampf Illustrated, a series of anti-Hitler political cartoons. As Rebecca Scragg has observed, 'The drawings began as a series of sixty in 1938, satirising selected quotations from Mein Kampf in order to make visible its portentous contents'. Scragg highlights 'Flatter's emphasis on Mein Kampf as the key to grasping the scale of the disaster that National Socialism would unleash' (Scragg 2005, p. 90). The series was adopted by war charities to form touring exhibitions entitled Mein Kampf Illustrated and Life of Hitler, shown in London shops (Boots, Piccadilly Circus; Selfridges, Oxford Street), and in Oxford, Birmingham and Cambridge, among other locations. In 1940 Flatter was interned as a so-called 'enemy alien' in Hutchinson Camp, Douglas, Isle of Man (known as the artists' camp, given the significant number of artist internees with established reputations). After release, he worked intermittently as a cartoonist with the Ministry of Information in London between 1940 and 1945. Some of his early work, carried out during a probation period in 1941, was intended as black propaganda to be dropped over enemy territory, but was not finally utilised because, at the time, there was 'no demand for his kind of work' (Vinzent 2006, p. 152). Flatter was, however, one of only two foreign artists (the other being Josef Bato) granted a drawing permit to make sketches of the Blitz and its aftermath. His cartoons appeared in the May 1941 issue of Free Austria, a monthly review produced by the Austrian Office; winter 1943–44 issue of Young Austria's journal Austrian Youth; the German-language newspaper Die Zeitung; and British and American newspapers including the Daily Telegraph, News of the World, News Chronicle, Evening Standard, Oxford Mail and National Jewish Monthly (Vinzent 2006, p. 152). In 1944, Flatter held a solo exhibition at the Austrian Centre (AC, of which he was an active member) at their Swiss Cottage premises. Flatter also worked for the Belgian government in exile and for pro-de Gaulle French publications, and served in the Home Guard. Later he became an official war artist and attended the Nuremberg War Trials for two weeks in February 1946 with cartoonist David Low. Flatter later wrote: 'I drew many hundreds of cartoons during the war and, to my surprise, ideas never failed me. The moving force was hatred, it took concrete shape before my eyes [...] I went about in the shape of my adversaries. I crept into their skin. I drew, hanged and quartered them' (Spartacus Educational website).
Flatter was naturalised British in 1947. Less is known about his postwar activity; Flatter's obituary in the Jewish Chronicle (7 October 1988) notes that during his later years he focused on picture restoration and researched the work of Old Master painters. In 1976 Flatter presented around 200 pen and ink drawings to the Imperial War Museum, London, which also holds his oral testimony. Flatter died in London in 1988. The estate of his wife Hilde Loewe-Flatter was passed to the German Exile Archive 1933–1945 (German National Library, Frankfurt) by their son Peter Flatter. Several of Flatter's cartoons were featured in the touring leg (Sayle Gallery Douglas, Isle of Man, and Williamson Gallery, Birkenhead) of Ben Uri's exhibition, Forced Journeys: Artists in Exile in Great Britain c. 1933–45 (2009–10).