Prince Nikola, who had been trained from infancy in martial and athletic exercises, spent a portion of his early boyhood at Trieste in the household of the Kustic family, to which his aunt, the princess Darinka, wife of Danilo II, belonged.
O príncipe Nicolao, que fora adestrado desde a infancia en exercicios marciais e atléticos, pasou unha parte de súa infancia adiantada en Trieste na casa da familia Kustic, a cal súa tía, a princesa Darinka, esposa de Danilo II, pertencían.