Chazan was the S.H. and Helen R. Scheuer Emeritus Professor of Hebrew & Judaic Studies at New York University, where, as founding chair of the Skirball Department of Hebrew and Judaic Studies, he championed dual-degree programs for future Jewish professionals through the Wagner School of Public Administration and the Steinhardt School of Education.

The author of nine books and dozens of articles, his work, according to the Encyclopedia Judaica, “is characterized by a nuanced perspective on Jewish-Christian relations that were not by any means always characterized by hostility.” In books like “In the Year 1096: The Jews and the First Crusade” and “Reassessing Jewish Life in Medieval Europe,” he depicted Jews “not only as victims but also as people actively confronting the core issues of the day in a manner that mirrors the efforts of the surrounding Christian majority.”

In 1998, he won the National Jewish Book Award in Jewish History for “European Jewry and the First Crusade.”

Chazan was born in 1936, the son of Abraham and Ida Chazan, and grew up in Albany, New York. He received his B.A. from Columbia College in 1958 and his rabbinical ordination from JTS in 1962. He taught at JTS as a graduate student from 1962–1967. At Columbia, he was a student of Salo Wittmeyer Baron, a pioneering figure in Jewish studies at Columbia from 1930 until his retirement in 1963.

At a Columbia seminar with the philosopher Justus Buchler, Chazan recalled, he was reluctant to describe his own career plans, assuming that there were few opportunities for a full-time scholar of Jewish studies. Instead, Buchler told him, “What a great idea … If you were finishing now, there wouldn’t be a job available for you.” But the American campus, said Buchler, “is going to change over the next decade and by the time you finish” there will be positions.

Buchler was prophetic. Chazan finished his dissertation, on 13th-century Jewry in Northern France, in 1967, “right at the point that a new program had been created at Ohio State, and I secured the new position.” He taught at Ohio State University from 1967–1980, where he also served as director of the Melton Center for Jewish Studies. After a brief stay at Tel Aviv University, Chazan moved to Queens College of the City University of New York, where he served from 1981–87, including as director of the Center for Jewish Studies. From 1987 has served as Scheuer Professor of Jewish Studies at New York University.

Among those paying tribute to Chazan was historian Jeffrey Woolf, who contributed an essay to the sixth volume of the “Cambridge History of Judaism,” which was edited by Chazan. “From our interactions I learned that not only was he a scholar of the first rank, he was also very much a mensch,” Woolf wrote on Facebook.

In addition to leading AAJR, Chazan was president of the Association for Jewish Studies from 1988–1991. “Studies in Medieval Jewish Intellectual and Social History,” a festschrift, or collection of essays in his honor, appeared in 2012. In their introduction, the editors noted his scholarship, his role in building the field of Jewish studies and his efforts training professionals dedicated to Jewish communal service and education.

“To all of these efforts,” they wrote, “he has consistently brought his impeccable scholarly credentials, his administrative acumen, and the integrity and friendship for which he is so well known.”

A list of survivors was not immediately available.