Edgar B. Hatrick III is the longest-serving superintendent in the Washington region. (Jahi Chikwendiu/The Washington Post)

The passing of the torch from former Loudoun County school superintendent Edgar B. Hatrick III to Eric Williams was made official Monday evening at a brief swearing-in ceremony in Ashburn, marking the first change in the school system’s leadership in more than two decades.

Williams, 49, who was previously superintendent of schools in York County, Va., competed against more than 60 other applicants for the job. He won the unanimous support of the county School Board, school officials said. On Monday, Williams became the county’s seventh superintendent.

School Board Chairman Eric Hornberger made the opening remarks at the ceremony before a crowd gathered in the School Administration Building.

“We’re all here for a very important event. We first want to welcome Dr. Williams to Loudoun County,” Hornberger said, before addressing the new superintendent directly: “We are very excited to have you on board and eager to see what you will do to lead what we believe is one of the best school systems in America, certainly in the commonwealth.”

Hornberger also thanked Hatrick, who was in the audience at Monday’s ceremony. The former schools chief — the longest-serving superintendent in the Washington region — was responsible “in a large part for building up this school system,” Hornberger said, prompting enthusiastic applause from the crowd.

Gary M. Clemens, Loudoun County circuit court clerk, led Williams through the brief swearing-in recitation: “I, Eric Williams, do solemnly swear that I will support the Constitution of the United States and the Constitution of the Commonwealth of Virginia, and I will faithfully and impartially discharge all duties incumbent upon me as the superintendent of Loudoun County public schools according to the best of my abilities, so help me God,” Williams repeated.

The room erupted into applause again, this time for the school system’s new leader.

“I am absolutely thrilled, and I appreciate you each coming out this evening to join me in this incredibly special occasion,” Williams said after being sworn in. “I’m incredibly honored to have the opportunity to serve as superintendent here . . . and build on the incredibly strong tradition of excellence in our schools, to sustain that excellence, to build on that excellence.”

Williams takes the helm of the region’s fastest-growing school system in the wake of a particularly tense and controversial budget season, one that left School Board members determined to prepare for the fiscal 2016 budget process by gathering information about the school system’s needs and plans as soon as possible.

Earlier in the year, the county Board of Supervisors adopted a fiscal 2015 county budget that raised funding for schools by about $70 million but fell about $38 million short of fully funding the amount requested by the School Board.

During the last budget cycle of his lengthy tenure, Hatrick warned that the school system needed more money to make up for years of deferred costs and to keep up with the growing student population and the opening of new schools. School Board members supported the vast majority of Hatrick’s proposed budget and sent a $949 million spending plan to supervisors for review.

But the supervisors had made it clear that they intended to avoid raising taxes for county homeowners, and the School Board was left with a sizable funding gap to fill.

With the hope of a smoother and less confrontational process next time, the School Board has begun to assess its needs and expectations for fiscal 2016. Williams is expected to join board members for a budget work session over the summer.

“I’m looking forward to working with the School Board in its relationship with the Board of Supervisors,” Williams said in an interview. “Having a new superintendent is a good opportunity, because it’s a fresh start.”

In the coming year, Williams said, he will focus on learning as much as he can about the county’s schools and communities.

“I’m going to need to really dive in immediately and make a ton of connections in the community, in terms of getting to know our schools, getting to know students, parents, staff members, getting to know the not-for-profit organizations in the community,” he said. “That’s a key part of the job in the first year, but there’s also the need to hit the ground running immediately.”

As School Board members focus on preparations for fiscal 2016 and beyond, Williams said, he is eager to work with them to develop a long-term strategic plan: “Where do we want to be in 2020, and how are we going to be there?”