The Romaniotes have been, and remain, historically distinct from the Sephardim, some of whom settled in Ottoman Greece after the expulsion of Jews from Spain and Portugal after 1492.

Large Romaniote communities were located in Thessaloniki, Ioannina, Arta, Preveza, Volos, Chalcis, Thebes, Corinth, Patras, and on the islands of Corfu, Crete, Zakynthos, Lesbos, Chios, Samos, Rhodes, and Cyprus, among others.

Today there are still functioning Romaniote synagogues in Chalkis (which represents the oldest Jewish congregation on European soil), Ioannina, Veria, Athens, New York City, and Israel.

The name Romaniote refers to the Eastern Roman Empire, also known as Byzantium, which included the territory of modern Greece, which this Jewish group inhabited for centuries.

[4] A Hellenistic Jewish synagogue was discovered in 1829 near the ancient military port of the capital of the island of Aegina by the Scottish-German historian Ludwig Ross, who was working for the court of King Otto of Greece.

The floor was covered for protection and was studied again by Thiersch in 1901, Furtwängler in 1904, E. Sukenik in 1928 and Gabriel Welter in 1932 under the auspices of the National Archaeological Service.

The mosaic floor of the synagogue consists of multi-colored tesserae that create the impression of a carpet, in a geometric pattern of blue, gray, red and white.

Today, only part of the synagogue's mosaic floor is extant, and it has been moved from its original location to the courtyard of the island's Archaeological Museum.

[11] The Romaniote rites represent those of the Greek-speaking Jews of the Byzantine (or former Byzantine) Empire, ranging from southern Italy (in a narrower sense the Apulian, the Calabrian and the Sicilian Jewish communities) in the west, to much of Turkey in the east, Crete to the south, Crimea (the Krymchaks) to the north and the Jews of the early medieval Balkans and Eastern Europe.

Judah Leon ben Moses Mosconi, a Romaniote Jew from Achrida edited and expanded the Sefer Josippon later.

[21][page needed] In the 12th century, Benjamin of Tudela travelled through the Byzantine Empire and recorded details about communities of Jews in Corfu, Arta, Aphilon, Patras, Corinth, Thebes, Chalkis, Thessaloniki, and Drama.

"Tree of Life", frequently a name of Romaniote synagogues) in Prousa in Asia Minor which passed to Ottoman authority in 1324.

The event of the conquest of Constantinople was written down by a Romaniote Payetan in a lament hymn, composed with several phrases from the Old Testament in the shibusi style.

Their numbers dwindled after that due to economic emigration; after the Holocaust and in the wake of World War II, there were approximately 1,950 Romaniotes left in Ioannina.

The Romaniote prayer rite (Nusach) as seen in the original Mahzor Romania and the Romaniote commentaries (Minhag) on Jewish exegesis and Jewish law, vary from those of the Ashkenazi, Sephardic and Mizrachi Jews, and are closer to those of the Italian Jews: some of these are thought to have been based on the Jerusalem Talmud instead of the Babylonian Talmud (see Eretz-Yisrael minhag).

Tobiah ben Eliezer (טוביה בר אליעזר), a Greek-speaking Talmudist and poet of the 11th century, worked and lived in the city of Kastoria.

Among the Romaniote Jews, tradition dictates, that the most holy Sefer Torah, the Law of Moses, be read with the scroll standing upright in its tik; it is considered improper to lay it flat.

The Mahzor of the Romaniote Kaffa Rite from the year 1735 gives the order to read the Megillat Antiochos in the Mincha of Shabbat Hanukkah.

Votive offerings made of silver as stars or tablets called shadayot were a thankful gift to the Synagogue of congregants who have received help, healing or salvation by God.

Shemarya HaIkriti who moved after 1328 to Negroponte prepared his supercommentary to Ibn Ezra and, circa 1346–47 wrote his Sefer Amasyahu, a handbook of biblical apologetics.

[45] Mordecai Komatiano has left a legacy of some fifteen works on astronomy, grammar (dikduk), biblical commentaries and piyyutim; some of the later have even been included in the Karaite prayerbook.

Biblical translations, piyyutim, folksongs, Ketubbot, liturgical instructions, glossaries, mystical texts and the use of Greek words in commentaries in Judaeo-Greek are known.

The only phonetic differences to Standard Modern Greek, which could be noted shortly after the war have been [x] > [s] before front vowels, unusual intonation patterns and some peculiar lexical items, mostly of Hebrew-Aramaic provenance.

[65] Almost all Romaniote Jews of the island of Crete, together with some resistance fighters, died on the ship Tanaḯs when it was torpedoed by the British submarine HMS Vivid on 9 June 1944.

The vast majority of Romaniotes have relocated to Israel and the United States, with the world's largest community located in New York.

It is believed that the Metroon, discovered in 1930 at the foot of the hill Hephaestion (Thesion) was used as a synagogue during its construction at the end of the 4th century CE (396–400).

This view was expressed by the archaeologist H. Thompson, from the American School of Classical Studies in Athens, but was not developed into a complete theory.

After a long time a Bar Mitzvah (the Jewish ritual for celebrating the coming of age of a child) was held in the synagogue in 2000, and was an exceptional event for the community.

Ancient historic texts mention that Jews lived in the region of Magnesia, Thessaly and in particular in neighbouring Almyros as early as the 1st century AD.

[87] In 2024, a team of researchers announced that a modern Romaniote Jewish man from Greece belongs to "a previously undiscovered" branch of the Y-chromosomal haplogroup J-P58 found to be "dating straight back 7,000 years to the Neolithic era.