The president and chairman of the Devon Horse Show and Country Fair were ousted in a private meeting Monday night hastily called by a group of board members just weeks before a scheduled election.

Amid allegations of secret land deals and undisclosed conflicts on both sides, the board of directors voted to replace president Sarah Coxe Lange with Richard M. O'Donnell, the current treasurer.

Also, chairman Henry Lafayette Collins III, who has served on the board for nearly 50 years, was replaced by Wayne W. Grafton.

"This was a bilateral majority decision that new leadership is necessary to move the organization forward in a positive, productive way," board member Mimi Killian said after the meeting, reading from a statement on behalf of the board.

The meeting constituted another drama for the storied Main Line institution, which has endured turmoil in the last year. Former president and chairman Wade McDevitt stepped down from his leadership roles and the board in March after he was accused by some of keeping the board in the dark about a plan to develop a retail center in Devon that included leasing some Horse Show land.

The Devon Horse Show and Country Fair Inc. board of directors was notified last week via e-mail of the special meeting, called by nine of the members. Some attended via telephone.

Collins and Coxe Lange were to be up for reelection at the board's annual meeting Jan. 15. Collins said he did not understand why the special meeting was necessary when the vote "could easily be done, if desired, at the annual meeting."

"It would be one thing if there was something drastic going on. There isn't," Collins said Monday afternoon.

Coxe Lange could not be reached for comment.

Attorneys had advised the signees of the e-mail calling the meeting not to speak to reporters, Killian said Monday morning.

In an interview, board member Joanna Glass praised Coxe Lange's work as president and said it was shocking that other board members "wouldn't appreciate what she's accomplished."

The board is split between members who work on the country fair side and those who work for the horse show, Glass said. Under the board's new bylaws, five independent members will also be part of the panel, Glass said, but they have not been chosen yet.

"This is a very inappropriate, poor-governance time to try to oust the president and the chairman," Glass said.

Killian's statement said the annual election was held in December in compliance with bylaws, referring to Monday's meeting.

Devon is known for its eponymous equestrian event, a late-spring competition that brings riders from around the world. The two-week-long event also includes the country fair, with crafts and food.

Orchestrated by board members involved with the fair, the ouster reflected long-running tension between the two camps.

The meeting was surrounded by murky concern over rumors that one faction or the other might want to sell the site and move the horse show to a different location.

Speculation has centered on McDevitt and Urban Outfitters, the prospective developer for McDevitt's retail project in Devon. The former president and chairman has various connections to the retail firm.

"There are absolutely no plans for us to acquire the Horse Show grounds, and there never have been," McDevitt said Monday afternoon.

Coxe Lange had been working to get a conservation easement for the property to help preserve it, Glass said. Coxe Lange and Collins would never want to sell the land, she said.

"Oh, good Lord, they're the last people to do that," Glass said.

Killian said the board's focus would continue to be supporting Bryn Mawr Hospital, the Horse Show's beneficiary.

"The community can rest assured that the Devon Horse Show and Country Fair is here to stay in Devon," Killian said in the statement.

Coxe Lange was elected in December 2013 and replaced McDevitt. Her tenure was marked by various changes, including establishing an endowment for the show and creating new bylaws that cut the board of directors from 52 members to 21.

Collins was named chairman in October after the new bylaws passed and was serving in the interim until the January annual meeting, he said.

Monday night's meeting, held at the Devon Courtyard Marriott, was closed to the public.

"That's not fair, because they have all the high-powered people in there," said Rich Scarlett, a longtime horseman who said he showed up to support the show at the request of someone in the meeting but was turned away.

Protesters had been expected, but only a handful of residents showed up Monday night.

The board statement said that "many divisive statements and false information" had been circulated and would be addressed in the coming weeks.

jmdaniel@phillynews.com 610-313-8205 @McDanielJustine