That Herr von Trapp in The Sound of Music was a submarine commander for the Austro-Hungarian navy in WW1, sinking the French armoured cruiser Leon Gambetta with the loss of 648 of her 785 crew, & his first wife was a granddaughter & heiress of Robert Whitehead, an Englishman who invented & built the first effective self-propelled naval torpedoes (including the type used by von Trapp) in Fiume (now Rijeka) in what was then Austria but now Croatia, for the Austro-Hungarian navy.
I'd heard of Whitehead, largely because his works in Fiume became Italian after WW1, & the business still exists in Italy (Whitehead Sistemi Subacquei, subsumed into a division of Finmeccanica-Leonardo last year) & still builds torpedoes, used by the Italian & many other navies. I had no idea of the Whitehead-von Trapp connection, or that von Trapp had been a submarine commander.