The National Gallery of Art’s upcoming exhibit “Private Treasures: Four Centuries of European Master Drawings” offers more than 100 dazzling artistic gems from a private collection and one very tantalizing central mystery: Who is the woman who amassed these works — most of which were acquired in an 11-year span?

“She wanted people to focus on the drawings,” said the show’s co-curator Andrew Robison, explaining why the collector chose to remain anonymous.

Indeed, the works spanning the 16th to 20th centuries, which go on view Sunday, are so good they almost are enough to distract from this question.

Still, one wants to know.

At a recent preview, Robison, who steadfastly declined to name the collector, dropped hints as to her identity.

There were insights into her personality — “Gentle, pleasant … old school you would say,” he noted — and her financial status (“A salaried person” who also “inherited money”). Even her relationship to God got a nod. “She is a spiritual person herself,” Robison confirmed. Hence, she could relate to the achingly beautiful religious works that form a sizable portion of the show and her collection. Among the highlights: 16th-century artist Agnolo Bronzino’s highly evocative chalk interpretation of “The Dead Christ,” with his lifeless left arm supported by an anonymous hand, and Giovanni Battista Tiepolo’s impressionistic ink, chalk and brown wash rendering of “The Annunciation” from the early 1700s. “One of the most perfect Tiepolo drawings that survives,” Robison asserted.

Robison also discussed the collector’s institutional allegiances. She’s a supporter of the Morgan Library and Museum (which organized the exhibit with the National Gallery and where it was earlier on view), Smith College, the British Museum and the Royal Academy of Arts.

He shed light into her decorating choices. “This sits on the desk in her guest bedroom,” Robison said, pointing to a postcard-sized John Constable seascape. And what about Caspar David Friedrich’s faintly Poeian drawing of “A Moonlit Landscape with Lovers and a Church,” with its sinister cemetery looming in the foreground? That “hangs on the wall in the den behind the lamp” in her apartment, he recalled.

There was even a brief glimpse into this woman’s upbringing.

Robison stopped in front of a loosely drawn charcoal of “An Elegant Lady of the 18th Century Holding a Fan” (1897) by Swedish artist Carl Larsson. “She had growing up a Swedish governess,” noted Robison, and she “loved” the idea of honoring her with a “Swedish drawing.”

Robison, who meets up with the collector at auctions around the world, admitted that the two shared a “personal friendship.” “She’s stayed in my house several times,” he said.

And the National Gallery, which hopes to eventually be the repository for many of the pieces in the show — 15 of the 112 works on display are either promised or already donated — appears to be banking on the relationship to reap dividends for its permanent collection.

For instance, when Fra Bartolommeo’s highly detailed ink drawing of “The Virgin and Child Surrounded by Saints and Angels” (the reverse of which features a kneeling angel and the very faint remnants of a standing man) from the early 1500s was offered for sale to the National Gallery, it opted “to turn the opportunity” over to the collector even though the gallery had long sought to acquire it. “She bought it to live with during her lifetime” but will give it to the gallery after her death, Robison said.

On some occasions, Robison even steps in to negotiate for her — as he did when she acquired “Two Studies of Saint Cecilia Playing the Organ” (whose backside was later discovered to contain a pair of studies of the Madonna and Christ child), circa 1648, by Pier Francesco Mola.

Given all these clues, it’s unlikely the mystery woman’s identity will remain shrouded for long. But in the meantime, could Robison at least divulge where she lived?

“In America,” he said. “She is American.”

Glad we cleared that up.

“Private Treasures: Four Centuries of European Master Drawings” is on view from May 6 to Sept. 16 at the National Gallery of Art’s West Building. For more information, visit www.nga.gov.