John Tlumacki/Globe Staff

Brad Stevens was introduced Friday as the 17th coach in Celtics history.

John Tlumacki/Globe Staff

Stevens, from Butler University, said he was "humbled" by his new role and "in awe" of the history that surrounds the Celtics.

John Tlumacki/Globe Staff

Celtics boss Danny Ainge, left, said he had been interested in Stevens as an NBA coaching candidate for several years, but never thought he'd be able to hire him.

John Tlumacki/Globe Staff

There were dozens of members of the media on hand at the Celtics’ training facility in Waltham for the introduction of Stevens.

John Tlumacki/Globe Staff

Stevens was joined by his wife, Tracy, who also negotiated his contract.

John Tlumacki/Globe Staff

Said Stevens: “I couldn’t be more thrilled for the opportunity."