'At the beginning of the war O'Brien joined the Australian Army Medical Corps and in 1940 was sent to Palestine and then almost immediately to Greece. There, when the day's duties were completed, he found some time to work. He painted mainly heads and his sitters were people of all ages and nationalities. Clearly, the tranquil portrait heads of the later 1950's and 1960's must, to some extent, have been pre-figured in the sketches painted during this time. At Ekali in Greece he was taken prisoner and was destined to spend the rest of the war in prison camps. After seven months in Athens he was sent to Torun in Poland where he arrived at the end of December 1941. Many of the studies he had made in Athens he was able to take with him to Poland.

The years spent in Poland were not completely wasted; he was able to complete a large number of drawings and he painted heads of other prisoners. The paints were provided by the Red Cross and for 'canvas', the cardboard containers of Red Cross parcels were used.

At the end of the war O' Brien returned to Australia and the pictures painted during the years in Poland were shown at the Macquarie Galleries, Sydney, in March 1944.' (Kenneth Hood, Justin O'Brien, in Art and Australia, December 1969, Vol. 7, Number 3, pp. 220-224)