Robert K. Webb, 89, a longtime history professor at the University of Maryland Baltimore County who was one of the country’s foremost scholars of British history, died Feb. 15 at his home in Washington. He had lymphoma, his daughter Margaret Webb Pressler said.

Dr. Webb, who usually published under the name R.K. Webb, was perhaps best known as the author of “Modern England: From the 18th Century to the Present,” which was first published in 1968 and remained a standard college textbook for more than 30 years. He wrote several other books and was also the co-author, with Yale historian Peter Gay, of another college textbook, “Modern Europe,” first published in 1973.

“He was, for a long time, the pre-eminent scholar of British history in America,” John W. Jeffries, a professor of history and dean of UMBC’s College of Arts, Humanities and Social Sciences, said Saturday.

UMBC, which was founded in 1966, was still a relatively unknown university struggling to establish an identity when Dr. Webb joined the faculty in 1975. He had been a full professor at Columbia University and the top editor of the country’s leading professional journal of history, the American Historical Review, before coming to UMBC as chairman of the history department.

“Bob gave us credibility,” Jeffries said. “He was not just a figurehead. He was important to the department and to the university.”

Robert K. Webb was perhaps best known as the author of “Modern England: From the 18th Century to the Present.” (Family photo)

Dr. Webb’s specialty was the intellectual history of 19th-century England, with a particular interest in the Unitarian religious movement and reforms associated with it. In 1960, he published a biography of Harriet Martineau (1802-1876), a British Unitarian who was also an influential voice for reform, particularly in the abolitionist movement in the United States.

A former student of Dr. Webb’s at Columbia, Linda Lear, recalled that when she was writing her 2007 biography of children’s book author Beatrix Potter, she regularly met with Dr. Webb to discuss Potter, who was a Unitarian.

“He was interested in every aspect of history,” Lear said. “He was the most erudite man I have ever come across in my life.”

Robert Kiefer Webb was born Nov. 23, 1922, in Rossford, Ohio. As a child, his daughter said, he was a piano prodigy and won a statewide competition in Ohio when he was 12.

He interrupted his education at Oberlin College in Ohio to serve in the Army in the Pacific during World War II. In the Army, he gave informal concerts on a troopship and taught history to his fellow soldiers.

He graduated summa cum laude from Oberlin in 1947 and was elected to the Phi Beta Kappa honor society. He received master’s and doctoral degrees from Columbia in 1949 and 1951, respectively. He studied at the London School of Economics on a Fulbright fellowship and received two Guggenheim fellowships and several research grants from the National Endowment for the Humanities.

After a short stint at Wesleyan University in Middletown, Conn., Dr. Webb was on the Columbia faculty from 1953 to 1970. While still affiliated with Columbia, he became editor of the American Historical Review in 1968 and moved to Washington, where the journal was then published.

His daughter said Dr. Webb continued to play piano and was known as an excellent cook. She said she and her sister could never find a word in the dictionary that he didn’t know.

Survivors include his wife of 54 years, Patty Shull Webb of Washington; two daughters, Emily Martin of Los Angeles and Margaret Webb Pressler, a Washington Post writer and editor, of the District; and six grandchildren.

In 1989, Dr. Webb was named UMBC’s first presidential research professor. He retired from teaching in 1992 but remained an emeritus professor until his death. A university lecture series in history is named in his honor.

“In some ways,” Jeffries, the UMBC dean, said, “he taught us all how to be good scholars and historians.”