The eldest child of a large family, de Mango was born in the town of Bisceglie near Bari in Italy, where he honed his native talent for drawing up to the age of nineteen.
In 1862, under the patronage of an aristocratic family of Bari, he entered the Academy of Fine Arts of Naples and studied there for eight years under Filippo Palizzi and Domenico Morelli. Morelli was a painter who treated exotic orientalist themes. During this period de Mango also worked with Saverio Altamura, Bernardo Celentano, Raffaele dAuria, Federico Maldarelli, Raffaele Postiglione and Giuseppe Mancinelli.