Born in Scalea (Cosenza) on 10 February 1886 to Giuseppe Armentano and Maria Alario, at the age of fifteen he moved with his family to Brazil, where relatives had been living for some time.
There he began to study music (piano and violin) and attended the Liberi Pensatori (english: free thinkers) club in São Paulo.
[5] In the same years the Rito Filosofico Italiano (english: Italian Philosophical Rite) was established, of which Armentano himself, with the nickname "Ermete Cosentino" and together with Arturo Reghini and Edoardo Frosini, became exponents.
He joined the Alpini corps, but was later transferred to Belluno due to an onset of heart disease and finally to a unit in Naples, far from the war scene.
It is widely believed in pagan, esoteric and Masonic circles that Armentano had a charismatic personality,[8] even possessing psychic powers, and it is said that after his departure for Brazil, his disciples continued to have a deep veneration for their Master.