Pastor Július Dérer was head of a Protestant girls’ school with a boarding section and an orphanage in the Slovakian town of Modra. Despite the danger to him and his family, Dérer hid around 30 Jewish girls there, passed off as Christians, from 1943.
In 1944 German soldiers and members of the Slovak militia attached to the Catholic nationalist Hlinka Party raided the orphanage premises. Dérer asked his daughter Viera to take the girls out of the building and hide them nearby. When some of them returned to the boarding school later, they were arrested and taken to Sereď camp. Dérer tried to free them, but did not succeed. Six Jewish girls went undiscovered during the raid, and lived in hiding in the boarding school until their liberation.
After the communists took power in 1948, Július Dérer was persecuted for criticizing the new Czechoslovakian state, and was not allowed to work as a pastor after 1957. He was honored by the Israeli Holocaust memorial center Yad Vashem as Righteous Among the Nations in 1996.