These two martyrs were unrelated, but their stories are similar. Both were Christians who embraced Islam at an early age under the Turks. Both later repented and, after doing penance, resolved to return to the place of their apostasy and accept martyrdom. Both presented themselves to the Turks, proclaimed their Christian faith, and were beheaded according to Islamic law.
Saint Nikodemos not only embraced Islam, but forced his family to do the same. One of his sons fled to the Holy Mountain and became a monk. The father pursued him there, but was moved to repentance by the holiness of the place and became a monk himself. After three years of penance, he resolved to return home to Albania and embrace his martyrdom.
Saint Nektarios converted to Islam (the Prologue says under duress) at the age of seventeen. When his mother saw him dressed as a Turk, she cried “Get away from me! I do not know you. I bore you as a Christian, not a Turk!” Repenting of his deed he went to the Holy Mountain and became a monk. Like St Nikodemos, he determined after a few years to return home and accept martyrdom for Christ.