Dennison Young Jr., a discreet, unflappable lawyer whose life became intertwined with that of his polar opposite, the volatile former New York City Mayor Rudolph W. Giuliani, as Mr. Giuliani’s top aide and confidant for decades, died on Feb. 13 at a hospital in Manhattan. He was 78.
Nicholas, Nicholas’ son, stated that cancer was the cause.
Mr. Young and Mr. Giuliani struck up a friendship in the early 1970s, when they were both prosecutors in the United States Attorney’s Office for the Southern District of New York — Mr. Young in the civil division and Mr. Giuliani in the criminal division — and they plowed through life together.
Mr. Young served as Mr. Giuliani’s right-hand man through Mr. Giuliani’s two terms as mayor, starting with his election in 1993. He was there when Giuliani Partners, a highly profitable security consulting firm, was formed in 2002.
The two men shared many life-defining moments. They both went through divorces and battled prostate cancer in the late 1990s. They were enjoying morning coffee when, on Sept. 11, 2001 the mayor learned that the World Trade Center was being attacked by a plane. He remained with him throughout the chaos, even when a second plane struck the second tower.
“We were trapped for half an hour, and the governor thought we were dead,” Mr. Giuliani said in a phone interview last week. “Denny was like a rock. He showed no fear.”
He said that Mr. Young was always the calmer one during their years together, which made for an odd-couple study of contrasts.
Mr. Young was a private man who was thoughtful, measured, thought and worked behind the scenes. He was compared to the former mayor, who was impulsive, voluble and operatic. “He was very careful,” Mr. Giuliani said. “I tend to be quick; Denny would put the brakes on when it was needed.”
This sometimes included managing the mayor’s temper. “If Rudy sees something in the papers that pisses him off, Denny tries to calm him down,” Dan Collins, co-author with Wayne Barrett of “Grand Illusion: The Untold Story of Rudy Giuliani and 9/11” (2006), said in a 2008 article in Gentleman’s Quarterly. “That was Denny’s job — to keep Rudy on the straight and narrow as far as excesses of his temper and angry phone calls to reporters.”
Mr. Young was also able to keep secrets. Mr. Giuliani, who is known to leave few thoughts unshared, said in the interview that he had trusted Mr. Young’s judgment and discretion so much that during his ill-fated 2008 campaign for president, he planned to name Mr. Young director of the C.I.A.
But for all their closeness, Mr. Giuliani said, Mr. Young, for health reasons, had disengaged several years ago from Mr. Giuliani’s political and business activities. This included his legal representation for former President Donald J. Trump. In that capacity, Mr. Giuliani had helped lead the effort to overturn the 2020 election of Joseph R. Biden Jr. as president based on false claims of voter fraud — claims that led to the temporary suspension of Mr. Giuliani’s law license. Mr. Giuliani is currently involved in legal storms involving investigations into the Jan. 6, 2020, insurrection at Capitol by a proTrump mob.
“Denny had no involvement in the Trump representation,” Mr. Giuliani said. “He wasn’t involved in any of it.”
Mr. Young’s son, Nicholas, said in an interview that when his father’s health began to decline a decade ago, “Dad reduced his workload at Giuliani Partners, eventually fully retiring from his day-to-day advisory activities.”
Still, he said, “Rudy remained one of Dad’s closest friends to the end.” Through the early lockdown days of the Covid-19 pandemic, Mr. Giuliani occasionally shared his home on Manhattan’s Upper East Side with Mr. Young, who lived by himself on the Upper West Side.
Dennison Young Jr. was birth in Tallahassee (Fla.) on August 1, 1943. His father was a doctor in wartime Army. Dr. Young moved his family to Hartsdale following World War II.