In undertaking the dangerous mission of rescuing as many Jews as possible from deportation, Dom Bruno found support among fellow monks at Mont-César, higher-ups in the Belgian church hierarchy, and even several family members, including his young nephew Michel Reynders (who was later knighted in Belgium). He built an underground network by establishing contacts with a number of existing resistance groups and individuals similarly engaged in rescue work. Several of these individuals, including van den Berg, paid with their lives for these humanitarian activities. Dom Bruno's major effort was finding families and institutions willing to hide Jews, especially Jewish children, in spite of the obvious risks. In this, he was most successful by appealing to the prospects' Christian faith and values. Consequently, many of the cooperating institutions were Catholic boarding schools, usually operating within the walls of convents or monasteries. Dom Bruno would personally accompany "his children" to their new homes or move them to new locations to prevent suspicion among villagers.