Internationally known Iranian historian and linguist Ehsan Yarshater died of old age in California on Sunday. He was 98.

Yarshater, who specialized in Iranology, was founder and director of the Center for Iranian Studies at Columbia University and editor-in-chief of Encyclopedia Iranica, a scholarly, groundbreaking, and comprehensive research tool authored by multiple scholars.

Iranica is dedicated to the broad and inclusive study of Persian civilization in the Middle East, the Caucasus, Central Asia and the Indian subcontinent as well as the history of Persian literature, offering a comprehensive history of its subjects.

The Center for Iranian Studies was renamed “Ehsan Yarshater Center” in August to honor Professor Yarshater whose legacy and dedication to the study of Persian history and culture was exceptional, Colombia.edu wrote.

Born in Hamadan in 1920, Yarshater earned a PhD in Persian language and literature from the University of Tehran in 1947 before entering London University, where he received a master’s degree and a PhD in Iranian philology in 1960. He went to Columbia in 1958 and founded the Center for Iranian Studies in 1968.

In 1961, Yarshater was appointed to teach Iranian studies at Columbia University. He is also known for a series of major undertakings.

He was the editor of a 40-volume translation of al-Tabari’s 10th-century history of the world; editor of some of the Cambridge history works on Iran; and founding editor of a classic multi-volume series on Persian history and language.

In the mid-1990s he was troubled by the fact that Persian poetry was being assigned to oblivion. As he once said, most English speakers are familiar with Omar Khayyam, but they do not know about the 13th-century poet Rumi or the 10th-century Ferdowsi, who wrote “Shahnameh” (Book of Kings) an epic poetry of 60,000 plus couplets.

To get the poetic record straight, he embarked on a new 20-volume collection of Persian literature in the belief that “if something has to be done, I have a feeling that I should start doing it.”