Galina Chumak is proud to be Greek, however foolish she knows that pride may be. It wasn’t anything she did, she points out, just the circumstance of birth into what may be Ukraine’s oldest existing ethnic group. The Greeks arrived in present-day Ukraine before the Tatars, before the Russians, before the Jews, possibly even before the Ukrainians themselves.

They were settlers from the civilization that we think of today as ancient Greece. They came to the Crimea — a dramatically mountainous peninsula that juts into the Black Sea — in the 5th century B.C., or maybe even the 7th, or just possibly, says Chumak, who once worked on archaeological digs there, the 9th. That would be before Homer got around to composing “The Iliad” and “The Odyssey.”

There are about 91,000 Greeks in Ukraine, according to the last census, but they don’t live in the Crimea anymore, and that fact lies at the heart of one of those arguments that Ukrainian Greeks love to bat around, and have been doing so ever since they left there in 1778....