(Joshua Roberts/BLOOMBERG)

Bill Livingood, the longtime sergeant at arms for the House of Representatives, will retire at the beginning of next year, House Speaker John Boehner’s office announced Thursday.

For the past 17 years, Livingood has served as the House’s chief law enforcement and protocol officer, a largely behind-the-scenes role that involves maintaining the security of lawmakers and of the House side of the Capitol complex. To the public, the sergeant at arms is probably best known as the person who introduces the president and other officials before each State of the Union address.

Boehner (R-Ohio) said in a statement Thursday that Livingood “has served the House during the most challenging times faced by anyone who has ever held this demanding position.”

“Bill’s hard earned and well deserved retirement will be a real loss for the House, but we are grateful that he has assembled an outstanding team of professionals who share his dedication to round-the-clock protection of Members, staff and visitors here in the people’s House,” he said.

Livingood, a 33-year veteran of the U.S. Secret Service, was first nominated to serve as sergeant at arms by then-House speaker Newt Gingrich (R-Ga.) in 1995; his nomination was later approved by the full House and has been re-affirmed by every Congress since then.

His tenure in the post has spanned incidents such as the 1998 Capitol shootings, during which two Capitol Police officers were slain; the Sept. 11, 2001 terror attacks; and the January assassination attempt against Rep. Gabrielle Giffords (D-Ariz.).

House Minority Leader Nancy Pelosi (D-Calif.) said in a statement that Livingood’s retirement “marks the end of an era defined by Bill’s dedicated leadership, sound judgment, and laser-like focus on what is best for the institution, its Members, staff, and visitors.”

“In some of the most challenging times for the House, such as 1998’s deadly attack on the Capitol Police, 9/11, and this year’s horrifying attempt on Congresswoman Giffords’ life, Bill Livingood has been a steady hand,” Pelosi said. “He’s overseen an era of greater security in the Capitol complex and an expansion in the responsibilities of the Capitol Police, always discharging his duties with bipartisanship and the utmost professionalism.”

Livingood’s retirement will be effective Jan. 17, 2012, the first day that Congress returns from its winter break. A House vote on Livingood’s to-be-named successor is expected to take place that day, according to Boehner’s office.