[gleeaikin]

Some Jews assimilated to avoid persecution.

I am not as knowledgeable about other parts of the world, but in Spain when Ferdinand and Isabela (around 1492) finally drove the Moors out of Spain, they insisted the Jews had to convert to Catholicism or also be expelled from the country. Both Moors and Jews left in large quantities which seriously hampered Spains intellectual development. Jews who stayed were labeled Conversos and not trusted. This was the time of the Spanish Inquisition, when large numbers of "heretics" were tried and burned at the stake.

[Hannah Senesh]

"but in Spain when Ferdinand and Isabela (around 1492) finally drove the Moors out of Spain, they insisted the Jews had to convert to Catholicism or also be expelled from the country."

Later, in Portugal, it was convert or die.

[chooseDoubt]

In Spain the reason why the Jews were evicted was basically because they had bank rolled the war and the Spanish didn't want to pay them back. The actual religious persecution was initiated as a means to an end, so the cause was finance and not a hatred of the Jewish people.