Throughout his tenure at Harvard, Clark has continued to play various leadership roles in the Mormon church, including as the bishop heading a congregation in Cambridge and as a Scoutmaster leading monthly camping trips for boys. He was a prominent supporter of the construction of a Mormon temple on a hilltop in Belmont and he visited the Globe in 2002 to discuss concerns about how his faith would be portrayed on the campaign trail and in the media as Mitt Romney prepared to run for governor.

"I had always thought at some point, once my service here at HBS ended, that if there was an opportunity to be involved in one of the church's universities, that that's something we could do," said Clark, referring to himself and his wife, Sue. "The common element in my thinking about all this was to try to put myself in a position to be of service and to do what I thought my Heavenly Father wanted me to do."

Harvard Business School, founded in 1908, has educated many of the nation's elite. BYU-Idaho, by contrast, was established in 2001 as a four-year institution. It is a successor to Bannock Stake Academy, founded in 1888 to educate Mormon pioneers and over time was renamed Fremont Stake Academy, Ricks Academy, Ricks Normal College, and then Ricks College.

"It has an ambition, a desire to become a great four-year school, and I felt that that was an opportunity to be engaged in really building an institution," Clark said. "There's a spirit of innovation on that campus, a desire to do things differently, to not be bound by the conventions of the academy, and to simply take on the challenge of educating and developing truly outstanding young people in the very best way we can figure out, and that's a very interesting prospect."

Harvard's president, Lawrence H. Summers, a longtime friend who once introduced Clark as "dean for life," said he made little effort to dissuade Clark from leaving.

"It became clear to me almost instantly that I was the president of Harvard and the president of Kim's church had spoken," Summers said at a news conference announcing Clark's departure. "And so I was best off accommodating the reality that I faced."

Sometimes departures are not forever. In Hehir's case, Harvard stayed in touch and continued offering the priest, who is an specialist on Catholic teachings about war and peace, opportunities to teach. So in 2003, when Archbishop Sean P. O'Malley brought Hehir back to Boston to head Catholic Charities here, Hehir also returned part time to the Harvard faculty, where he is now teaching one course a semester at the John F. Kennedy School of Government.

Clark, like Hehir before him, said he was unconcerned about the perception that he was leaving a high-visibility post for a little-known job.

"I think issues of prestige and stature are socially constructed — they get established in various kinds of interactions that we have in society, and they show up in the culture in different ways," Clark said. "People of faith walk around, in their heads, with a very different way of framing the world and deciding on what's important and what's not."