Bp. Nestor was born Baron Nikolai Pavlovich Zakkis on December 20, 1825, in Arkangelsk, Russia. The family was a member of the Russian gentry. His education was secular, beginning when he entered the naval program at the Alexandrovsk Cadet School on May 20, 1832. On January 31, 1836, he transferred to the naval cadet school. As his naval career advanced he was in turn promoted in 1842 to the rank of reefer and then to midshipman, and then on to lieutenant in 1849. Due to illness, however, he was discharged from the navy in late 1850.