Arthur H. Thornhill Jr. died on Dec. 17 in Charlottesville, Va. He was 91 and had been a longtime seasonal resident of the Vineyard.

For 25 years he served as president and CEO of Little, Brown and Company, the prestigious publishing house founded in Boston in 1837. His college education at Princeton University was interrupted by World War II while he served nearly four years in the U.S. ground and air forces in the Pacific Theatre before returning to Princeton and completing a degree in American history in 1946. Two years later he joined Little, Brown and Company as a trainee and worked in various sales and editorial departments. He was named general manager of the trade division in 1954, elected a vice president in 1955, and became president of Little, Brown, Ltd. (Canada) in 1956. He rose to the position of executive vice president in 1959, and finally, to president and CEO in 1962, succeeding his father Arthur H. Thornhill Sr. (1895-1970).

One of Mr. Thornhill’s major achievements was negotiating the 1968 merger in which Little, Brown became a subsidiary of Time Inc., while retaining an independent board of directors, a Massachusetts charter and full editorial control in all publishing decisions.

Major authors published by Little, Brown during his tenure include Norman Mailer, Herman Wouk, Ansel Adams, Lillian Hellman, John Fowles and Henry Kissinger. He expanded and developed the law, medical and college text divisions of the company, and ventured into trade paperback publishing. He was also involved in a variety of activities and organizations both inside and outside the publishing industry, chairing, for example, the American Book Publishers Council’s Committee on reading development and serving on the board of trustees of the Princeton University Press, Bennington College, and the Martha’s Vineyard Preservation Trust, and as a fellow at the Center for Creative Photography at the University of Arizona.

In 1987, Mr. Thornhill retired from Little, Brown. Thereafter, he and his wife Dorothy, who died in 2013, divided their time among residences in Virginia, Florida and Martha’s Vineyard.

He was a member of the Union Club, the Century Club, the St. Botolph Club, the Edgartown Yacht Club, the Edgartown Reading Room, the John’s Island Club and the Farmington Country Club.

He is survived by a daughter Sandra Brushart, a son Arthur 3rd, and four grandchildren.

A memorial service will be held later in Duxbury. Condolences may be sent to the family at hillandwood.com.