Nikoghayos Ter-Hovhannisyan was born to an Armenian family in the village of Kyshlak (today Gyshlag or Tsaghkashat) in the region of Nagorno-Karabakh, then a part of the Russian Empire.

Duman was the initiator of the 1897 Khanasor Expedition, an attack on the Kurdish Mazrik tribe and its commander Sharaf Beg for their role in the Hamidian massacres and ambush at Van, and took part in the campaign as a squad leader.

All of the men in the tribe were killed and only the women and children were spared, a mercy the Turks and Kurds never gave the Armenians.

He also took part in the Persian Constitutional Revolution, leading the ARF forces during the defense of Tabriz.

Feeling that he would not be able to participate with the other Armenian fedayi, Duman committed suicide with a pistol shot on the evening of 23 September 1914.

Nikol Duman's house museum is located in his native village of Kyshlak in the Nagorno-Karabakh Republic.