After the invasion of Yugoslavia in April 1941, the Ustasha movement established the Independent State of Croatia (NDH) whose territory included today's Croatia, with the help of Hitler and Mussolini. Following ideals of national pureness, Ustasha began immediately a policy of extermination of the Jews and also of the Serbians, whose number in NDH reached almost two million. Massacres, expulsions and conversions from the Orthodox to the Catholic church were the main methods, as well as concentration and extermination camps. Serbs, including men, women and children, were brutally executed or died of starvation and disease. In this context, Diana Budisavljević, an Austrian married to a Serbian doctor from Zagreb, decided to help Serbian women and children in concentration and extermination camps in October 1941. It was the beginning of the “Diana Budisavljević Action”, an aid project organised by Diana that continued until the end of the war, giving material support to women and child inmates (principally food and clothes) and saving children from extermination. It was calculated that the “Diana Budisavljević Action” managed to release almost 12,000 children from the major camps such as Jasenovac and Stara Gradiška. For almost fifty years after the end of the war, the history of Diana and her action remained unknown. After the war, communist security service agents took complete documentation of Diana. So the thousands of Serbian children left in the Croatian families. Most of them never knew their true origin.