Sotheby’s has appointed Marc Porter chairman of its Fine Art Division, where he joins fellow chairs Allan Schwartzman and Amy Cappellazzo at the helm of the auction house’s specialist departments and advisory businesses.

Porter, who’s scheduled to start on January 17, will also lead Sotheby’s global business development strategy, and will be based in New York.

“With more than 25 years in the art market, Marc is uniquely suited to take on an important leadership role at our company,” said Sotheby’s CEO Tad Smith. “Coupled with his experience and excellence serving clients, his business acumen nicely complements our superb team of specialists around the world.”

“Sotheby’s is at the forefront of many of the most dynamic changes happening in today’s art market,” Porter said in a statement, “and the combination of our expansion into new services and capabilities, with established leadership and an outstanding and committed team, makes it a particularly exciting time to join.”

News of Sotheby’s poaching Porter from competitor Christie’s first broke in December 2015, but at the time no specific position was named for him.

“He will take on a role that will empower him to bring his decades of global experience in fine art to bear on the needs of our most valuable clients around the world,” Smith said in a statement back then.

Now, after a year spent on “gardening leave,” Porter’s position at Sotheby’s has finally been revealed.

At the time, his hiring was seen as a major coup for Sotheby’s, as Porter has been an important asset for Christie’s for over 25 years, holding several top positions during that period, including chairman and president of Christie’s America.

“I left because of my own feelings about what kind of business I want to lead,” Porter said in December 2015, in an interview with the New York Times, referring to the frustration he felt about Christie’s decision to break down the global private sales division—which he headed from 2012 to 2015—into individual departments.

A consummate deal-maker, during his tenure at Christie’s Porter secured the consignment of some of the most important single-owner collections, including those ofHollywood star Elizabeth Taylor, and Robert Ellsworth, a top dealer in Asian art. He also pioneered online sales and mediated a number of high-profile restitution cases.