 Zaruski was also noted for leading a rescue expedition that saved Maria Bandrowski, who was trapped in the Tatra Mountains with her brother, the Polish philosopher Bronisław Bandrowski.At the start of the First World War he organized 11th Polish Cavalry Regiment and became its commander.For his bravery during the offensive on Wilno City on 16 April 1919, he was decorated with the highest Polish Military distinction the Order of Virtuti Militari 5th Class and several times with the Cross of Valour.