The president of Columbia University, Lee Bollinger, will take the summer off, exiling himself to Vermont after five years managing crises and raising money in Morningside Heights.

A spokesman for Columbia, David Stone, said that after serving 11 consecutive years as a university president, first at the University of Michigan and then at Columbia, Mr. Bollinger is taking a “trustee-approved period off campus.”

The absence comes at a critical time for the university, which is in the midst of a $4 billion capital campaign that is among the largest in the history of American higher education. It has also embarked on a vast physical expansion plan on 17 acres north of its current Manhattan campus.

Such a leave is not unprecedented for Ivy League presidents, who work a schedule that is by many accounts physically and mentally demanding. The president of Harvard, Neil Rudenstine, took a three-month leave in the winter of 1994-95, citing exhaustion and prompting an avalanche of articles on the daunting challenges facing modern university presidents.

Mr. Bollinger, 62, won’t be resting but working on several book projects, among them a book on freedom of the press, which, when complete, will be a volume in a series from Oxford University Press on aspects of constitutional law. Mr. Bollinger, whose academic background is as a legal scholar of free speech, teaches a popular class for undergraduates on the First Amendment.

“He’s been president for five years, and you need a break after five years, particularly if you’re writing a book,” said a professor of English and comparative literature at Columbia, Jean Howard. “I think it’s great, I think presidents need time to recharge their batteries.”

Mr. Bollinger had an eventful academic year. In the fall, the president of Iran, Mahmoud Ahmadinejad, a Holocaust denier who has vowed to wipe Israel off the map, visited campus. Shortly thereafter, a professor at Columbia Teachers College, Madonna Constantine, told police she had found a noose hanging on her office door.

In November, five students began a hunger strike, demanding that Columbia’s core curriculum include more non-Western classes and that more money and resources be allocated to the Office of Multicultural Affairs. In the spring, Mr. Bollinger named a new dean of Columbia’s School of International and Public Affairs, John Coatsworth, a defender of Castro’s regime in Cuba and an advocate of divestment from Israel.

Nearly 300 miles away from campus in Norwich, Vt., Mr. Bollinger is in regular contact with his colleagues, Mr. Stone said. Some said they did not know he had left.

“I wasn’t aware that he was away,” said a history professor, Richard Billows. “A lot of professors are too busy with their own work to be paying attention to that.”