Costantini was born in Cefalu, Italy, he studied at the Royal Academy in Venice and in Paris. He moved to London where he exhibited at the RA, RSA,RI,ROI and GI. He was strongly influenced by JS Sargent and Lucien Simon. He taught for a time at the RA schools. His subject matters were varied , from landscapes, figurative subjects and portraits. He was also a sculptor. He died in Rocquebrune.