In “The Divine Comedy,” the 14th-century poem by Dante Alighieri that is one of the foundational works of Western literature, the Roman poet Virgil serves as Dante’s guide through Hell and Purgatory en route to Paradise. It is a revelatory journey but an arduous one, spanning 100 cantos and nearly 15,000 lines replete with references to the Florentine political scene, Christian theology and the world of antiquity.

For the past seven centuries, readers have pored over Dante’s words, beginning with the famous opening lines of the “Inferno”:

Midway in the journey of our life

I came to myself in a dark wood,

for the straight way was lost.

For the past 50 or so of those 700 years, students and scholars alike have relied on Robert Hollander as a guide, a Virgil to their Dante, as they made their way through Dante’s masterpiece.

Dr. Hollander, a professor emeritus at Princeton University who died at 87, was widely regarded as a preeminent Dante scholar of his era. With his wife, the poet Jean Hollander, he produced a translation of “The Divine Comedy” that was hailed as one of the finest and most erudite English versions rendered from the original Italian.

Earlier in his career, beginning in the 1980s, Dr. Hollander helped lead his fellow medievalists into the Internet age by organizing initiatives including the Dartmouth Dante Project and the Princeton Dante Project, online databases that allow readers to explore the text of “The Divine Comedy” along with centuries of commentaries on the poem and other materials explicating and elucidating Dante’s work.

“He was a man who had really big ideas,” said Teodolinda Barolini, a professor of Italian at Columbia University and, like Dr. Hollander, a past president of the Dante Society of America. Reflecting on his three monumental undertakings — the two online projects and the translation of “The Divine Comedy” — she remarked that “most people are happy” if they achieve only one such feat.

Dr. Hollander was best known beyond academia for his and his wife’s edition of “The Divine Comedy.” (The “Inferno” was released in 2000, the “Purgatorio” in 2003 and the “Paradiso” in 2007.) Numerous English translations of “The Divine Comedy” or parts of it had preceded the Hollanders’ works, including notable attempts by the poets W.S. Merwin and Robert Pinsky. But many reviewers regarded the finished Hollander product as a thing apart.

“If you haven’t yet read the Divine Comedy — you know who you are — now is the time, because Robert and Jean Hollander have just completed a beautiful translation,” New Yorker writer Joan Acocella declared in 2007 after the release of their “Paradiso.”

“It is more idiomatic than any other English version I know,” she continued. “At the same time, it is lofty, the more so for being plain.”

The translation was not only a fruit of the Hollanders’ marriage, but also a marriage of their talents. Jean Hollander, the author of several books of poetry, took on the translation of the verse — an already herculean task made more difficult by the challenge of re-creating Dante’s terza rima tercets in English. Her husband provided the explanatory notes, which, by Acocella’s estimate, ran 30 times the length of the poem itself.

“His more than 40 years of teaching Dante gave him many insights into the poem which he incorporates into the commentary,” Christopher Kleinhenz, a professor emeritus of Italian at the University of Wisconsin at Madison, said in an interview. “He has made Dante accessible,” Kleinhenz continued, so that “we as contemporary readers can appreciate and can see how Dante was important in the Middle Ages and how he continues to be important today.”

The Hollanders embarked on their project in 1997, the New York Times reported, when Dr. Hollander was laboring over a 1939 translation of “The Divine Comedy” by John D. Sinclair.

“It was awful,” Jean Hollander told the Times, “not poetic . . . and it really read very badly. So my husband challenged me. He said, ‘Well, can you do better?’ ”

She tried and, they agreed, she did — setting the couple’s course for the next 10 years.

By the end of their project, Acocella observed, Dr. Hollander in his commentary “comes to sound like one of the blessed” in Paradiso as Dante imagined it. “He wants nothing other than what he has. After four decades of teaching the Divine Comedy, he feels close to Dante.”

Robert B. Hollander Jr. — the middle initial stood for nothing — was born in New York City on July 31, 1933. His father was a financier, and his mother worked as a nurse before becoming a homemaker.

Dr. Hollander studied at Princeton, where he received a bachelor’s degree in French and English in 1955, and then at Columbia University, where he received a PhD in 1962 with a dissertation on the Scottish poet Edwin Muir. He and his wife, the former Jean Haberman, met during graduate school and married in 1964.

Jean Hollander died in 2019. Their daughter Elizabeth Hollander died in infancy.

Dr. Hollander’s survivors include two children, Zaz Hollander of Palmer, Alaska, and Robert B. “Buzz” Hollander III of Paauilo, Hawaii; a brother; and four grandchildren.

Dr. Hollander told the Times that in the early years of his academic career, he had little interest in Dante. He taught a course at Columbia whose required reading included “The Divine Comedy,” he said, and recalled thinking, “This is the greatest work of the Middle Ages?”

His mind was changed, he said, when he came upon a particular work of literary criticism that opened his imagination to Dante’s genius. “I walked out of the library having decided that I was going to be a Dante scholar,” he told the Times.

Dr. Hollander was hired in 1962 at Princeton, where his class on Dante, according to a Princeton publication, became known as “the organic chemistry of the humanities.” He wrote books including “Allegory in Dante’s Commedia” (1969) and “Dante: A Life in Works” (2001) and received grants for his digital endeavors from institutions including the National Endowment for the Humanities. Dr. Hollander took emeritus status in 2003.

Beyond his work as a Dantista, as specialists in the works of Dante are known, Dr. Hollander was a respected scholar of Giovanni Boccaccio (1313-1375), the author of “The Decameron” and another pillar of Italian literature. Although separated in time by centuries, they had something in common: Boccaccio was, as Dr. Hollander noted, the “first practitioner” in the study of Dante.

Dr. Hollander died April 20 at the Hawaii home of his son, who said the cause was congestive heart failure. When the Italian news agency ANSA reported the news of Dr. Hollander’s death, the outlet did not fail to note that it preceded by only several months the 700th anniversary of Dante’s death, which will fall in September.

The Hollanders were renowned in Italy, where they received the Gold Florin award from the city of Florence in 2008 for their translation of “The Divine Comedy.” After years of toil on their shared project, they had agreed that whoever outlived the other could revise the translation as he or she saw fit. The agreement, Dr. Hollander told the Times in jest, fueled a “tremendous incentive to stay alive.”