His younger brother was named Ioannis His great-grandfather, also a Konstantinos Dailakis, had opposed for several years the Albanian Sali Bey who wished to turn Verniki into his estate.

Until the end of 1901, he targeted local Ottoman dynasties in collaboration with the Internal Macedonian Revolutionary Organization after being promised Bulgarian sympathy towards Greeks.

In 1902, he met Konstantinos Kottas Christou in Korestia became a Makedonomachos under his command and fought against Bulgarians groups and Ottoman forces.

The two Makedonomachoi took revenge a few days later by killing Komitadji, Dine Yannev, and arresting Lazar Poptraykov, sentencing him to death (he later escaped).

After the death of Kottas in 1904, Nikolaos Dailakis would get in contact with many other chieftains, regional Greek elites, and church officials to organize armed resistance groups.

In early 1905, Nikolaos Dailakis arrested and executed Komitadji Christos Sapkarov and raided Bulgarian hideout with other Chieftains such as Georgios Tsontos.

In 1907, he left for Athens for the arrangement of weapon procurements and on his return, exterminated the Romanian Tsakamakas, who was partially responsible for the betrayal that resulted in the death of Pavlos Melas in 1904.