Janet Griffin, who has steered Folger Theatre on an adventurous Shakespearean course, announced Wednesday that she will retire March 31 after 30 years as its artistic leader.

The announcement means the departure of one of Washington’s longest-serving theater chiefs and an opening in a company with a prestigious literary pedigree: It is an arm of one of the world’s great classical collections, the Folger Shakespeare Library.

Rather than use that perch to offer lovers of Shakespeare conventional fare in tights and ruffs, Griffin filled the 265-seat Elizabethan-style space with inventive interpretations of popular and lesser-known works. Her taste for ingenuity led to invitations to experimental groups such as New York’s Fiasco Theater, which debuted a zesty “Two Gentlemen of Verona” in her space in 2014. She forged bonds, too, with a cadre of forward-thinking directors such as Aaron Posner, who, with magician Teller, staged an illusion-packed “Macbeth” in 2008.

“It’s always tricky to know when to step away,” Griffin, 68, said in a phone interview. Noting that the library is closed for a two-year, $72 million renovation, she added that this is a good time for a transition.

“I felt as though we created a mature program model that [library director] Mike Witmore and I have been tweaking,” she said. For her part, she explained, the company “deserves a new vision, somebody who can devote long-term energy. My God, I’ve been here for two-thirds of my life.”

The Mississippi native fell in love with theater while pursuing a graduate degree in Ireland. She started at the library, which is a stone’s throw from the U.S. Capitol, in 1977 and became its director of public programs five years later. The job title would later change to director of programming, but Griffin’s vision has been remarkably consistent. Since 1991, she has been in charge of producing plays, poetry series and other performances in the Folger’s intimate, two-tiered theater. The additional title of artistic producer passed to her several years after Michael Kahn took his classical company out of the space to found the Shakespeare Theatre Company.

Griffin’s demeanor doesn’t fulfill one’s preconceived notions of an impresario: She is soft-spoken and not prone to publicly tooting her own horn. But that reserved facade masked a passion for putting on a show.

“Janet is a determined person with really good judgment,” Witmore said. “That has meant she has not been hogging the spotlight. She believes in the work. She doesn’t have to promote herself.”

Over the years, Griffin has managed the difficult assignment of cloaking a company dependent on old texts in a contemporary relevance. Whether it was Posner’s revolutionary take on “Measure for Measure” in 2006, or the adaptation of Jane Austen’s “Sense and Sensibility” by New York’s Bedlam theater in 2016, she seemed intent on defying expectations rather than just meeting them.

“She was the person who was trying to get Shakespeare out into the world, and not just into the hands of the academics,” said Holly Twyford, an actress who has appeared in many of Griffin’s productions — which totaled more than 100 over 29 seasons. (Of the 36 plays in the Shakespeare canon, Griffin staged 29, several more than once.)

There was always, of course, the danger of doing stodgy theater in an institution devoted to research, where an orthodoxy in the library stacks might rein in creative exploration on the stage. Griffin avers that the opposite proved to be the case — that because Folger is a center of imaginative investigation, her productions found a receptive audience inside the institution as well as among Washington-area theatergoers.

“It’s clear almost in the architecture of the building there was meant to be performance side by side with the research,” she said. “The greatest thing about the Folger is being able to sit in the room with a director, actor and a scholar and have a conversation about the text.”

As plays had to share the library’s performance space with other programs, the Folger’s theater seasons tended to be shorter — three or four productions, rather than the six or seven at other major Washington companies. But in a city that loves its Shakespeare, it has had a particularly devoted audience.

“It has been one of the most important artistic homes in my life,” said Posner, one of a small cadre of directors (Robert Richmond, Richard Clifford, among others) on whom Griffin has relied. “When the Shakepeare Theatre left, the logical choice would have been to stick to more historical work — to look backward.

“She did the opposite,” Posner added. “The choice to not look backward and lead into exploration was transformative for those audiences.”

The Folger under Griffin’s stewardship also occasionally delved into the work of 20th- and 21st-century playwrights working in classical veins, such as Tom Stoppard (“Arcadia”) and Peter Shaffer (“Amadeus”). Such contemporary dramatists as Theresa Rebeck, Craig Wright and Caleen Sinnette Jennings tried out new work for her. Some of Griffin’s risks turned out to be of more academic than dramatic interest, as was the case with the staging of a Restoration-era “Macbeth” in 2018. But a passel of actors flourished during her Folger years. The list of notables, too numerous to name them all, includes Ian Merrill Peakes, Craig Wallace, Kate Eastwood Norris, Caroline Clay, Tom Story, Zach Appelman, Erin Weaver, Louis Butelli, Rick Foucheux, Eric Hissom and Todd Scofield.

Of late, Griffin was on an active search for more artists of color, hiring, for example, Rosa Joshi in 2019 to direct a production of “Henry IV Part 1.” It was a deeply meaningful chance for the Seattle-based Joshi to expand connections and her classical range. “I was very committed to having a diverse cast, and Janet really supported that idea,” said Joshi, who has since joined Folger’s board.

As Folger embarks on a search for her successor, Griffin looks back with gratitude. “It has been a great privilege for me to have the breadth of these plays,” she said.

One aspect of the job she won’t miss: biting her knuckles during the rapier-swinging battle scenes.

“I always hated the sword fights,” she said. “The moment when Ian Merrill Peakes jumped off the stage with a dagger, and Ruth Bader Ginsburg was seated on the aisle, I just cringed.”