On March 9, Bloomberg reported the passing of John “Jack” Byrne, the former chair of White Mountains Insurance Group, who is best known for turning around GEICO from near bankruptcy in the mid-1970s and taking Fireman’s Fund public.

An obituary posted on the website of the Rand-Wilson funeral home in Hanover, N.H., notes that Byrne died after a long battle with cancer on Thursday Mar. 7, and details his beginnings in the insurance industry, helping out in his father’s insurance agency as a teenager in Wildwood, N.J., and his rise to industry leader.

Byrne, who studied actuarial science, took his first job outside of his father’s agency on the life side of the business—at Lincoln National Life. He became a member of the American Academy of Actuaries in 1966.

A video biography of Byrne posted on the website of the International Insurance Society’s Insurance Hall of Fame, which inducted him in 2009, notes that he served a stint in the Air Force before moving into the life insurance industry, and after graduating from Rutgers and earning a Master’s degree from the University of Michigan.

In the property/casualty business, Byrne held leadership roles at Travelers before accepting the task of turning around GEICO in 1976. Various sources also describe Byrne’s subsequent leadership of Fireman’s Fund, after rescuing GEICO from what could have been the largest insolvency at the time. Byrne is credited with taking Fireman’s Fund public in 1985 in the largest IPO of its time. Later, after selling the insurer to Allianz to 1900, Byrne continued to lead White Mountains Insurance Group, the financial services holding company.

In addition to other accolades from his peers, Warren Buffett reportedly called Byrne the “best manager” in the industry and “the Babe Ruth of Insurance” after the GEICO turnaround.

In 2001, Byrne was selected as “Insurance Industry Leader of the Year” by the St. John’s University School of Risk Management.

He has served on the boards of Integro Insurance Brokers, American Express, Martin Marietta, Lehman Brothers, MidOcean, Financial Security Assurance, Zurich Re, and the International Special Olympics, among others.

Byrne summed up his approach to leadership on the IIS video. “I have been in the business world since 1943 and I always run the company as if I owned 100 percent of it myself,” he said.

Byrne is survived by his wife, Dorothy, three sons, and seven grandchildren, according to the funeral home announcement. In lieu of flowers, the family requests that contributions be made to Palliative Care at Norris Cotton Cancer Center or the Upper Valley Haven, both in New Hampshire.