The second youngest of five sons, Prince Gelasio Caetani was born in Rome in 1877. In 1903 he graduated from Columbia University's School of Mines. He dug gold in Idaho and filled several other mining contracts before founding the firm of Caetani, Burch & Hershey in San Francisco. When Italy entered WW I, he returned home and joined the Italian army engineers. In April 1917 he led the successful tunneling attack with explosives that destroyed a strategic Austrian fort on top of Col di Lana. Promoted to Colonel by the end of the war, Gelasio Caetani won three decorations for bravery. In 1922 as a supporter of Mussolini, he became Italian ambassador to the United States.