240 A History of Judaism
after 70, and Jews puzzled out their religious ideas not just in Hebrew,
Aramaic and Greek but in Arabic, which for a few centuries became the
lingua franca across most of the Jewish world, and more local lan-
guages. We shall see in the chapters that follow how individual Jews
moved from one community to another – from Palestine to Babylonia
or in the opposite direction in late antiquity, or from Spain to France to
Germany or England, or east to Poland or Russia – bringing with them
religious ideas and customs. A plethora of letters in the Cairo Genizah
reveals a desire for formal contact for religious advice as well as trade
and more mundane matters.
Despite such contacts, Jewish communities developed at separate
speeds and in divergent ways. We shall see that the end of ‘medieval’
Judaism came much later in parts of eastern Europe than in Germany.
The separate treatment in this book of the history of Judaism in the
early modern period from 1500 will be more valuable in illuminating
religious change in Italy and Holland than in, for instance, Yemen (see
Part IV). But we shall also see the frequent evidence of contacts between
Jews encouraging unity despite the recognition of difference.