Most people lucky enough to live to the age of 90 might mark the day with a cake and some presents. But for Bernard Lewis, a man considered the world’s foremost historian of Islam and the Middle East, the occasion is cause for a seminar on Islam and the West.

And while most 90-year-olds would be content to see their families on their birthday, Mr. Lewis will be celebrating his with a senator, a former secretary of state, a top television news anchor, and a very senior White House official whose locations are usually not disclosed. On Monday, Senator Biden, Henry Kissinger, Judy Woodruff, and Fouad Ajami will join Mr. Lewis at the Philadelphia World Affairs Council to discuss such weighty matters as “Domestic Security and International Image”and “Europe: A Fracturing Union.”

Mr. Lewis’s girlfriend, Buntzie Ellis Churchill, wrote in her invitation to Mr. Kissinger, “As the president of the World Affairs Council of Philadelphia and lady in Bernard Lewis’s life, it’s just easier to plan a conference than it is to bake a cake.”

There are few academics or historians who have matched the achievements of the emeritus Princeton University professor. He has written more than 24 books, received 15 honorary degrees, and fluently speaks, according to Ms. Churchill, eight languages which include the four languages of the Middle East – Arabic, Hebrew, Persian, and Turkish – as well as Danish.

A former student of Mr. Lewis’s and scholar at the American Enterprise Institute, Ruel Marc Gerecht, said his book, “The Muslim Awakening of Europe,” is “one of the best history books ever written. It is one of the rare history books that has a chance to still be read 50 years after it was published.” Even his rivals acknowledge his intellectual power. The late literature professor Edward Said built much of his popular theory of Orientalism, the view that Western analysts and historians write about indigenous cultures as a rationalization for their exploitation, as an attack on Mr. Lewis.

Mr. Lewis debated Mr. Said and author Christopher Hitchens in 1983 on the topic of Orientalism that many of Mr. Lewis’s followers believe marked the decline of their mentor’s field. “They believed it was a predatory conspiracy of western imperialists,” Mr. Lewis said. “I took the view this was a legitimate branch of scholarship. Since then the Saidian view has triumphed in western universities.”

Mr. Lewis’s ideas about the Middle East are also more current today than they were 30 years ago. His name is invoked almost constantly by critics of neoconservatives for the counsel he provided to Vice President Cheney about Iraq and the Middle East. Mr. Lewis first met with the vice president in 1990 on the eve of the first Gulf War. On the eve of the Iraq war, Mr. Cheney went on NBC’s “Meet the Press” and called Mr. Lewis “one of the great students” of the Middle East.

Mr.Lewis says his role in shaping war policy has been exaggerated. “I do meet people and talk to people I am not a consultant or adviser. I do not have any security clearances,” he said.

“To say Bernard is a double barreled fan of democracy in the Muslim world is not exactly right,” Mr. Gerecht said. “What Bernard Lewis has shown is the extent to which a lot of very bad Western ideas have implanted themselves in the Muslim world. The better one, the hardest one to absorb, democracy, has not. But there is reason to believe that might be changing.”

On a deeper level, however, Mr. Lewis has become one of the most relevant intellectuals on the region in the twilight of his life. In 1976, he wrote an essay for Commentary called “The Return of Islam” that made the case that Islam was emerging as the primary way Arabs identified themselves and predicted the rise of Islamic demagoguery. At the time, this insight deflated much of the claims of the waning pan-Arabists of the region. In 1978, Mr. Lewis began translating the writings of Ayatollah Khomeinei – before the 1979 revolution in Iran. His scholarship provoked the late senator, Henry “Scoop” Jackson, to ask the CIA formally about the exiled cleric in Paris, who famously insisted his writings (since proved not only authentic but prescient) were forgeries. Mr. Lewis wryly notes that the only texts of Khomeini’s “Islamic Government” were in Persian and Arabic. “This meant that most of Washington could not understand it,” he said.

Professor Samuel Huntington has even credited Mr. Lewis with coining the phrase, “conflict of civilizations.”

Born in London in 1916, Mr. Lewis became interested in studying the Middle East, according to Ms. Churchill during his bar mitzvah. “With his bar mitzvah, he started to learn a new alphabet and that is when he began to learn his first foreign language,” she said. Mr. Lewis attended the University of London at the time as opposed to Oxford and other schools because it was the only institution to offer a degree in Middle Eastern history and not just Arabic.

Ms. Churchill, who talks about him in glowing terms, praises especially his wit in conversation and his ability to “speak in complete and perfect paragraphs.” This skill has served him well in the last 20 years since retiring from teaching, she said. Mr. Lewis composes his books now from dictation.

But perhaps the highest praise Mr. Lewis has received is from his students, who say that despite his high reputation he has devoted time to mentoring. “You know when you are in his presence you are in the presence of a historical wonder,” Mr. Gerecht said. “For those of us who believe that life is about time-tripping, there is no greater joy in this world than to be with Bernard Lewis.”