House Speaker William J. Howell (R-Stafford), left, confers with Del. S. Chris Jones (R-Suffolk) during the 2017 session of the Virginia House of Delegates. (Bob Brown/AP)

Speaker William J. Howell, a pragmatic Republican who has presided over Virginia’s fractious House of Delegates for 15 sessions and spent the last four as a thorn in Gov. Terry McAuliffe’s side, will not seek reelection in November.

Howell, 73, announced his decision Monday in emotional remarks in the ornate House chamber, with his wife of 50 years, Cessie, and other family members looking on.

“I have really enjoyed serving in this esteemed body,” Howell said. “It has truly been the greatest professional honor of my life.”

Even before it was officially announced, Howell’s plan to retire at the end of his term in January set off a competition between two delegates to replace him at the helm of the overwhelmingly GOP-majority chamber.

House Majority Leader M. Kirkland Cox (Colonial Heights) and Del. Terry G. Kilgore (Scott) worked quietly over the past week to line up support for their rival bids to replace Howell (Stafford), according to two Republicans familiar with their efforts. They spoke on the condition of anonymity to discuss internal caucus matters.

Kilgore has since withdrawn. “I just didn’t think it was the right time for me,” he said. Cox declined to comment, saying that “this is the speaker’s day.”

The House GOP caucus is expected to name Cox its speaker-designee in a close-door meeting Wednesday.

House members on both sides of the aisle praised Howell on the floor not only for his political leadership but also for a quick wit that could defuse tense situations and for a sense of personal friendship.

“I think after I called my parents, you’re the first person I called after I adopted my kid, that’s how much I think of you,” said Del. David B. Albo (R-Fairfax), his voice breaking. “You are proof, Mr. Speaker, that nice guys can finish first.”

House Minority Leader David Toscano (D-Charlottesville) praised Howell for standing up to his own party on an off-year redistricting scheme in 2013. Senate Republicans had tacked an entirely redrawn state Senate map onto a bill calling for minor “technical adjustments” to House districts. Howell ruled it out of order, a move that infuriated some Republicans.

“You are truly a historic figure in this chamber and in this Capitol,” said Toscano, adding that the speaker is akin to a judge. “The good judges are the ones who let you try your case. . . . You let us try our cases, and we thank you for that.”

Howell’s relationship with McAuliffe (D) has been strained, despite their shared history as dealmakers and McAuliffe’s efforts to woo the speaker over craft beer in the Executive Mansion.

Howell has used his position — among the most powerful in state government — to help thwart many of the governor’s biggest goals, including the expansion of Medicaid under the Affordable Care Act, the appointment of a state Supreme Court justice and the blanket restoration of voting rights to more than 200,000 felons.

With a lawsuit filed last year to block the restoration of felons’ voting rights, Howell became the first speaker in the history of the commonwealth to successfully challenge a governor’s executive order in court.

“On behalf of the people of Virginia, I want to thank Speaker Bill Howell for his outstanding service to Virginia,” McAuliffe said in a statement. “I have tremendous respect for the Speaker and the professional and dignified way he led the House throughout his tenure. I wish him the very best in his retirement.”

Howell is Virginia’s second-longest-serving speaker, behind Democrat Edgar Blackburn Moore, who held the post from 1950 to 1968.

Deemed “the accidental speaker” because he assumed the role in January 2003 after S. Vance Wilkins resigned amid a sexual harassment scandal, Howell instituted a number of reforms, including bringing some strictness and objectivity to rules governing what can be ruled in and out of order.

A member of the House since 1988, Howell was one of four delegates to start a prayer group that still meets at 7 a.m. every Wednesday during the session. He has been a conservative on social issues such as abortion.

But he also sought to keep a lid on some hot-button bills after they consumed the 2012 legislative session. Del. Robert G. Marshall (R-Prince William), one of the chamber’s most vocal conservatives, often complained that Howell had some of his bills quietly killed off in committees to avoid controversy. An example of that this year was Marshall’s ill-fated measure to require transgender people to use the public bathroom that corresponds with the sex on their birth certificates.

Howell has primarily focused on promoting business-friendly policies. And he has been willing to cut deals to get things done — sometimes to the chagrin of more ideologically driven Republicans.

Among those deals were some involving McAuliffe’s predecessors. Howell spoke out against Democrat Mark R. Warner’s $1.6 billion tax hike but quietly instructed a few Republicans to skip a committee vote so that the bill would go the House floor. Despite his distaste for Democrat Tim Kaine’s smoking ban, he struck a deal there as well. He signed on to the transportation plan of Republican Robert F. McDonnell, even after the legislation was amended into the largest tax hike in Virginia history.

“It’s really Bill Howell’s greatest legacy,” said Del. Mark Sickles (D-Fairfax), referring to the transportation funding measure. “We’d still have smoking in restaurants for that matter.”

A wills and trusts lawyer who practices in a log cabin on the Rappahannock River, Howell assumed the speakership at a time when his party enjoyed a slim majority in the 100-seat chamber. Their numbers swelled as high as 68 during his tenure, which also saw the adoption of a 2011 redistricting map favorable to Republicans. Two lawsuits — one before the U.S. Supreme Court, the other before a state circuit court — challenged the constitutionality of the maps.

Presiding over that growing majority became tricky with the rise of more conservative, tea-party-affiliated members, who looked askance at Howell’s pragmatic streak.

In 2014, some conservative Republicans said they feared that Howell was secretly on board with McAuliffe’s plan to expand Medicaid as they pushed for a budget amendment that they thought was needed to tie the governor’s hands. The speaker had called the amendment unnecessary but eventually got on board. McAuliffe later acknowledged that the amendment blocked a loophole that he had intended to use to expand Medicaid unilaterally.