became the main Jewish district after the Jews were moved there from the city proper in 11th century; after the period of Latin rule the Jews were concentrated in
Vlanga on the shore of the
Sea of Marmara (
Volanga on the map) Although the Justinian Code remained in force in the Eastern Empire until the ninth century, the period following Justinian's reign was generally characterized by toleration of non-Christians, particularly the Jews. However, during the
Byzantine–Sasanian War of 602–628 many Jews sided against the
Byzantine Empire in the
Jewish revolt against Heraclius, which successfully assisted the invading Persian Sassanids in conquering all of Roman Egypt and Syria. In reaction to this, anti-Jewish measures were enacted throughout the Byzantine realm and as far away as
Merovingian France. Soon thereafter, in 634 the
Muslim conquests began, during which many Jews initially rose up again against their Byzantine rulers. During this time
Heraclius became the first emperor to force the conversion of Jews to Christianity. Following his death, and until 1204, the Jews suffered only three notable legal persecutions, the sum of whose span was roughly fifty years. It is even debated whether the first of these—the anti-Jewish measures passed during the reign of
Leo III the Isaurian—could be considered a persecution. The second of these, during the reign of
Basil I from 867 to 886, briefly punctuated the tolerance of the ninth century.
Asaph the Jew wrote in Byzantium the first Hebrew medical treatise. The
Sefer Yosippon was written down in the 10th century in the Byzantine
south Italy by the
Greek-speaking Jewish community there.
Judah Leon ben Moses Mosconi, a Romaniote Jew from
Achrida edited and expanded the
Sefer Josippon later. This community of Byzantine Jews of southern Italy produced such prominent works like the
Sefer Ahimaaz of
Ahimaaz ben Paltiel, the
Sefer Hachmoni of
Shabbethai Donnolo, the
Aggadath Bereshit and many
piyyutim. The liturgical writings of these
Romaniote Jews, especially the piyyut were eminent for the development of the
Ashkenazi Mahzor, as they found their way through Italy to
Ashkenaz and are preserved to this day in the most ashkenazi mahzorim. Like in the case of the Hellenistic Jewish authorship some of the Byzantine Jewish manuscripts show the use of the Greek language in religious and communal aspects. The language of this manuscripts is not in
Ancient Greek, but rather in an
older form of
Modern Greek. These texts are the oldest known written texts in Modern Greek. Beside these Rabbanites and as a part of the Empire's Romaniote Jews, important
Karaite communities like the
Constantinopolitan Karaites and the Karaites of
Adrianople flourished and produced eminent personalities for the Karaite movement like
Caleb Afendopolo,
Elijah Bashyazi,
Aaron ben Joseph of Constantinople,
Aaron ben Elijah,
Judah Hadassi and other. In the twelfth century, there were about 2,500 Jews in
Constantinople, 2,000 Jews in
Thebes and 500 Jews in
Thessalonica.
Halmyrus,
Rhaedestus,
Chios, and
Rhodes each housed 400 Jews. Also, there were about 300 Jews each in
Corinth and
Samos, and 200 Jews in
Gallipoli. Some Jewish families in the rural provinces of the empire, such as
Thrace,
Moesia, and
Pannonia Secunda, appear to have maintained distinct communal practices shaped by local customs and Hellenized liturgical traditions. These frontier communities often remained outside major urban centers and were less affected by imperial persecutions or theological controversies. Archaeological and genetic studies suggest a degree of regional continuity among these populations, which may have preserved older forms of worship and maternal lineage traditions into the High Middle Ages. It was in the 12th century that the passing
Crusaders wrought havoc upon the Jewish communities of Byzantium, in a foretaste of what the later
Latin occupation would bring upon the Byzantine Christians. Although most crusading bands did not adopt a policy of violence or forced conversion against the Jews, the
First Crusade certainly undertook an anti-Jewish face in certain communities. Because the Crusade was undertaken with the goal of "subjugating all non-believers to the faith," many crusaders compelled Jews to convert on pain of death, and there is a large number of recorded cases of mass suicides within Jewish communities—particularly among Jewish maidens—in order to avoid such conversions. ==Latin occupation: 1204–1261==