The definition and significance of the word “national,” may be clear to many in the United States, but when used in certain countries like Greece, “national” carries a whole other connotation, a historian said Wednesday at Harvard University.

For the Greeks, Alexander Kitroeff said, nationalism has been a constantly changing concept “rooted in language, religion and history.”

Kitroeff, who is an associate professor specializing in modern Greece, explained his ideas about Greece’s nationalism to a small group of about 10 graduate students and professors as part of the Humanities Center at Harvard Seminar on Modern Greek Literature and Culture.

One of the main themes discussed was that of the ‘Great Idea,’ which resulted from Greece’s original formation as a nation.

Kitroeff compared this process to the creation of the 13 colonies in North America. He said the Greeks during this time wanted to expand into nations and regions that had other ethnic Greeks living within their borders.

Kitroeff also said there is a typically negative view that Greek nationalism is “irrational as well as ethnically exclusionary.”...