Since 1953 Yad Vashem, the Holocaust Martyrs' and Heroes' Remembrance Authority in Jerusalem, has been conferring the title "Righteous among the Nations" (Chasidei Umot Haolam) to those who lent assistance to persecuted Jews in the Nazi period. In so doing they often put at risk not only their lives, but those of their loved ones. Those honoured receive a commemorative medal and the Yad Vashem Certificate of Honour; their names are entered at the institution and engraved on the Wall of Honour in Yad Vashem's Garden of the Righteous. Among the Righteous are more than four hundred citizens of the Slovak...