Former UNC-Chapel Hill law dean Gene Nichol resigned abruptly Tuesday as president of the College of William & Mary in Virginia after a series of political controversies.

In a letter to the William & Mary community, Nichol said he was informed Sunday by college leaders that his contract would not be renewed in July. He stepped down immediately, he said, and refused an offer of "substantial economic incentives" to remain quiet about what he described as ideological disputes behind his departure.

He said he made several decisions that ignited a furor at the public college in Williamsburg, including moving a cross in a historic chapel used regularly for secular college events -- citing principles of separation of church and state. He also refused to ban controversial performances from campus on two occasions. Nichol also worked to diversify the campus through a new scholarship aimed at poor students.

"As the result of these decisions, the last sixteen months have been challenging ones for me and my family," he wrote in the letter. "A committed, relentless, frequently untruthful and vicious campaign -- on the Internet and in the press -- has been waged against me, my wife and my daughters."

That campaign included Virginia legislators, Nichol said, who threatened college board appointees unless Nichol was fired.

The most recent dust-up involved the Sex Workers' Art Show, a traveling performance that stirred criticism when it came to Duke University earlier this month. Nichol refused to ban the show, which was paid for with student fees and planned by students.

In a passionate letter that quoted William & Mary alumnus Thomas Jefferson, Nichol acknowledged that he had not been a perfect president.

He wrote that "it is crucial not to surrender to the loud and the vitriolic and the angry -- just because they are loud and vitriolic and angry."

In a parting shot, Nichol was indignant about an offer from college leaders that he hinted was hush money.

"I add only that, on Sunday, the Board of Visitors offered both my wife and me substantial economic incentives if we would agree 'not to characterize [the nonrenewal decision] as based on ideological grounds' or make any other statement about my departure without their approval," he wrote. "Some members may have intended this as a gesture of generosity to ease my transition. But the stipulation of censorship made it seem like something else entirely."

A William & Mary spokesman said Nichol would not comment beyond his letter.

The college's board of visitors released a statement Tuesday that praised Nichol for his energy, passion and commitment to diversity but said a change of leadership was needed to address problems keeping William & Mary from its full potential.

"It is critical to explain that this decision was not in any way based on ideology or any single public controversy," the statement said. "To suggest such a motivation for the board is flatly wrong. Indeed, the board has been repulsed by the personal attacks on the president and his family."

Nichol's letter said he would return to the law school faculty at William & Mary.

Nichol was dean of UNC-CH's law school from 1999 to 2005. In 2000, he was a finalist for the chancellor's position that eventually went to James Moeser. UNC-CH now has a search committee looking for a successor to Moeser, who will retire this year.