Al Hirschfeld fairly Forrest Gump-ed his way through the celebrated entertainers of the 20th century, whether he was meeting Harry Houdini backstage during a vaudeville-loving boyhood, or welcoming Charlie Chaplin to his Bali abode, or witnessing a young Orson Welles stage an upstart opening that birthed the Mercury Theatre. The man — as artist — seemed drawn like a moth to the fame.

But the remarkable story of Hirschfeld — including the stage and screen history he bequeathed to us — centers on just how many of these stars he drew, and just how many of their live performances are frozen in time through his balletic line.

Hirschfeld, who died in 2003 at age 99, is enshrined in the dramatic arts, virtually perched on the Mount Rushmore of modern entertainment caricaturists as firmly as his name adorns a Broadway theater on West 45th. Now, after artists such as Charles Schulz and Theodor Geisel have received definitive biographies, Hirschfeld finally joins them on the shelf of popular American illustration.

Ellen Stern, who once interviewed the artist for a GQ article, trots out a trove of breezy anecdotes — her present-tense prose at times galloping to keep up with Hirschfeld’s travel-happy younger years — to capture the colorful life behind his quill-pen line that, in its light and fluid grace, has summoned metaphoric comparisons to Fred Astaire.

Here is the St. Louis-born boy suddenly transplanted to New York, where by his teenage years he’s drawing promotional images for major film studios. He then makes art while living in London, Paris (where he first sprouts his signature long beard) and the Soviet Union in his 20s, but it is while he is soaking up Indonesian sights in 1931 that the sun-bleached environment alters his experimental eye. “Everything was pure line,” he says. “The people became line drawings walking around. I knew that my life would never be the same.”

Hirschfeld had begun drawing drama-page art for newspapers in the 1920s, thanks to a press agent who spotted his sketching and smartly took it to the New York Herald Tribune. Much in demand during this golden era, he began his long association with the New York Times by 1928 and debuted in Vanity Fair several years later.

The elegant swoops and loops. The exaggerated eyes and mouths. The fields of patterned hatching. And all that clean composition. Hirschfeld, while nodding to his artistic influences, soon became a style unto himself. After he caricatured the Marx brothers, the film studio sought to restyle Groucho to look more like a humorous Hirschfeld.

Stern deftly reflects Hirschfeld’s warmth and wit in recollecting these heady decades, such as when the illustrator, being paid by the newspaper column inch, draws his art within sweeping pennant and pie-slice shapes that stretch across several columns and are heavy on the white space. “A swindle of the most horrifying kind,” Hirschfeld says. “I had a lot of fun.”

Then, when his only child was born in 1945, Hirschfeld began the twist for which his work is also inextricably famed: He “hides” daughter Nina’s name in a newspaper artwork, and then another, and soon readers wouldn’t let him stop. They relished this secondary seek-and-find game, which made its way into academic studies and mental acuity tests, and later turned Nina herself into a reluctant celebrity. Says Hirschfeld, “This little folly was, over the decades, to turn into a monster.”

Hirschfeld: The Biography” fizzes along merrily when describing his life as a bon vivant and slows the pace appropriately when times grow more difficult, such as when his beloved second wife dies, or when the struggling adult Nina moves back home and fights with her father.

Yet as fertile as Hirschfeld’s life is, Stern’s stories are most engaging when the focus returns to the art. Hirschfeld’s illustrations were interpretive of theatrical and film productions — that is part of his genius — and celebrities could be sensitive about their caricatured features. Behind-the-canvas anecdotes are delicious, such as when “Candid Camera” host Allen Funt complained that Hirschfeld made him look like a simian. The artist’s cheeky reply later: “I had nothing whatever to do with the way Mr. Funt looked. That was God’s work.”

“Hirschfeld” also carefully delves into some late-career controversies, such as when the Times tried out a replacement artist; when squabbles over the use of his art arose between people in his employ; and when Time magazine rejected a Hirschfeld drawing of Louis Armstrong judged to be too evocative of a Sambo caricature. (The author notes that James Earl Jones is among those in Hirschfeld’s corner.)

Mostly, though, Stern paints a thoughtfully textured portrait of the man in the blue jumpsuit who sat in his Koken barber chair — the “most functional chair in the land,” he liked to say — and drew most days from morning to dinnertime, at peace alone while re-creating the world as a poetic flow of India ink.

If “Hirschfeld” leaves the reader wanting in any area, it is that the prose stokes the appetite to see pictures. This is not intended to be an art book by any means, yet only one image shows his caricatures. To experience the artist is to gaze at his art. So beyond his collected art editions, a reader might do well to watch the excellent 1996 Academy Award-nominated documentary “The Line King” as a companion piece to this biography. Or you might browse the Al Hirschfeld Foundation’s digital exhibitions.

“In the theater, a playwright can create a character with a few brilliant lines,” Liza Minnelli says in a clip within that film, while honoring Hirschfeld at the 1993 Tony Awards. “The theater has been blessed by the presence of a great artist who can create a single brilliant line and tell you everything about a character.”

Hirschfeld infused his line with life. “Hirschfeld” sharply fills in the life behind the line.

Hirschfeld

The Biography

By Ellen Stern

Skyhorse.
442 pp. $27.99