Leone Jacovacci (a.k.a. John Douglas Walker and Jack Walker) was born in 1902 in the village of Pombo in the then Belgian Congo (now Democratic Republic of the Congo), the son of an Italian man and a Congolese woman.

He was raised in Italy which was rough for him, given that he was bi-racial, and as a result, in his late teens, found himself in England where he reinvented himself as John Douglas Walker, added a couple of years to his age, and enlisted in the 53rd Battalion of the Bedfordshire Regiment of the British Army.