I was very sad to hear about the passing of Chuck Feeney. He was one of my personal heroes and one of the greatest philanthropists of all time.

Chuck had four important traits that made him so special.

First, he was totally dedicated to giving away everything he had. In the 1980s, at the height of his entrepreneurial success, he gave his entire stake in his company to his foundation and then spent the next 32 years awarding all of that money to nonprofits around the world. He and his foundation helped build more than 1,000 buildings across five continents, and yet Chuck decided he didn’t even need to own a home. After giving away his $8 billion fortune, he and his wife lived in a rented apartment.

Second, Chuck started humble and stayed humble. He was born during the Depression and had a very modest upbringing in New Jersey. He went to college on the G.I. Bill after serving as an Army radio operator during the Korean War. Once his wealth enabled him to start giving away huge sums of money, he insisted on doing so without any publicity; his giving was strictly anonymous until his identity was revealed in 1997. Chuck wanted to give away his entire $8 billion fortune without anyone outside his immediate circle knowing.

Third, he was passionate about philanthropy. I’m sure he felt pride at what he created in his business life, including not only Duty Free Shoppers but also the investment firm General Atlantic Partners. But I know he got a lot of personal satisfaction helping solve big social problems around the world. He loved meeting people, learning about issues, and thinking about the best ways to help out with his time, knowledge, and money.

Fourth, as a result of all of the above, he was a very effective philanthropist. He had a major hand in bringing about the Irish Republican Army ceasefire in 1994 and the historic peace agreement in Northern Ireland. His “big bets” helped rebuild Vietnam’s primary health care system for the benefit of millions of rural families. In education and health care, he helped his grantees build strong institutions that will produce meaningful, measurable change for many years.

I had the honor of meeting Chuck at the time Melinda, Warren, and I were starting to think about launching the Giving Pledge. We were blown away by how approachable he was. And we could tell immediately that Chuck really enjoyed giving. As he later put it when he joined the Giving Pledge, “I cannot think of a more personally rewarding and appropriate use of wealth than to give while one is living—to personally devote oneself to meaningful efforts to improve the human condition.”

Despite his soft-spoken nature and desire for anonymity, he was always glad to talk about what he was learning in the hope of helping others find the same joy and impact that he did. As a result, he had a very positive influence on many other givers. He inspired others to think about the merits of spending down a foundation’s assets, or as he put it, “giving while living.” He helped donors see how rewarding it was to get deeply and personally involved. His bold stand on HIV encouraged others to support advocacy.

I’m grateful to have known and learned from Chuck. His remarkable legacy will live on for generations to come, through all of the organizations he strengthened and all the ways he influenced others to give of their fortunes and of themselves.