Siggi made his fortune in oil and banking: He was the former CEO of Wilshire Oil Company of Texas and the former chairman of the Trust Company of New Jersey, per his obituary in the New York Times.
The Wilzig brothers used to be bankers like their father, but have since found new callings. Alan is now an entrepreneur and motorsport racer, while Ivan is an electronic dance music artist and reality star who goes by the stage names "Sir Ivan" and "Peaceman."
On Instagram, Ivan regales his 14,500 followers with snaps of himself alongside bikini-clad women at parties, promotion for his father's biography, and photos of his "Peacemobile" — a tie-dye limo with the word "Peace" emblazoned on its side.
As for where he got the name "Sir Ivan" from, it all started with a license plate: Ivan got matching vanity plates for himself and his brother that said "Sir Ivan" and "Sir Alan" on them when they moved into the castle.
"I thought I was being cute with those on our cars," Ivan said.