In 1920, he received his first teaching appointment with the Presbyterian Church of Nigeria and Church of Scotland at Itigidi and two years later became a senior tutor at St. Paul's Teachers' Training College, Awka, Anambra State.
Born in Nawfia-Awka, a village near the Igbo city of Onitsha in Nigeria, Nwankwo attended University College in Ibadan, gaining a BA in 1962.
Historians have compared the significance of Nri, at its peak, to the religious cities of Rome or Mecca: it was the seat of a powerful and imperial state that influenced much of the territories inhabited by the Igbo of Awka and Onitsha to the east; the Efik, the Ibibio, and the Ijaw to the South; Nsukka and southern Igala to the north; and Asaba, and the Anioma to the west.
It is said that Eri canoed down the River Anambra and established a place known as Eri-Awka.