Henri Reynders was born to an upper class catholic family in Brussels, Belgium on 24 October, 1903.
Henri Reynders became a monk at the young age of 17, and was ordained a priest in 1928. Becoming a priest, he changed his name to Dom Bruno.
With the Nazi invasion of Poland in September 1939, Belgium mobilized its military. Dom Bruno decided to serve, and did so by joining the 41st Artillery Regiment as a chaplain.
During the Battle of Dunkirk, King Leopold of Belgium surrendered his armies to the Nazis (this would include Dom Bruno). Bruno would spend the next 6 months of his life at various POW camps such as Wolfsburg and Doessel.
In November 1940, King Leopold met with Adolf Hitler, and as result, over 50,000 Belgian POWs were released from camps all over Europe. One of those released was Dom Bruno. Bruno would continue to teach religiously (as he did before the war).
In 1942, the Gestapo gave permission to Dom Bruno, so that he could work in a house for the blind. While working there, he realized that the owner and several residents (adults and children) were actually Jews in hiding. Armed with this knowledge, he decided to try and help them hide from the Nazis. With the help of Albert Van Den Burg.