Two lesser-known, but important people associated with Peter Drucker, John E. Flaherty and Tony Bonaparte, passed away in recent years. Flaherty died in 2016, and like Drucker, lived to be 95. Bonaparte died in 2014 at the age of 76.

Both men considered Drucker to be a mentor, but their roles in Drucker’s life, and their professional accomplishments, went well beyond that. Both had long and distinguished careers in academia, including, coincidentally, as Dean of the Lubin School of Business at Pace University in New York. Bonaparte also had a lengthy association with St. John’s University.

Flaherty and Bonaparte came into contact with Drucker in the midcentury years when he was a professor at New York University. It was a crucial period in Drucker’s life, when he wrote some of his most important books, such as The Practice of Management, Managing For Results, The Effective Executive, and The Age of Discontinuity. In 1970, as Drucker was leaving NYU to move to Claremont, California and what would eventually be called the Drucker School of Management, Flaherty and Bonaparte edited and each wrote essays for Peter Drucker: Contributions to Business Enterprise, a special volume in tribute to Drucker from a variety of contributors, such as Drucker’s longtime friend Marshall McLuhan, Harvard Business School’s Theodore Leavitt, and the pioneering British management guru Lyndall Urwick.

I interviewed Flaherty for a USA TODAY piece on his book, published to coincide with Drucker’s 90th birthday in 1999, Peter Drucker: Shaping the Managerial Mind. Flaherty told me that he first audited a Drucker class at NYU in the mid-50s, and then went to every Drucker lecture he could for the next dozen years. In the article I wrote that the 445-page book “amounts to a complete introductory course on the life and work of Drucker….” It remains essential reading for anyone who wants to gain an informed sense of Drucker’s work, on management and beyond.

Bonaparte was interviewed by Elizabeth Edersheim for her 2007 book The Definitive Drucker, on how Drucker changed his life when he was an Executive MBA student at NYU. “He made sure I always was stretching just a little further,” Bonaparte told Edersheim, “liberating me from my constraints. Each time I went back, my expectations of myself were higher. He would not let me do anything but succeed. And if it weren’t for him I wouldn’t be where I am today.”

In recent years, we have seen the passing of some of Drucker’s most important associates, as I have written about recently in posts about Bob Buford, Max De Pree, and T. George Harris. Reflecting on their lives, and those of Flaherty and Bonaparte, is a reminder of how Drucker attracted high-achieving people into his orbit, and how they became even more accomplished and consequential under Drucker’s influence.