Roots and Perseverance of Anti-Semitism

Why, indeed, is anti-semitism, the oldest and most enduring form of hatred known on Earth?

After all, Jews have contributed mightily to human progess. Jews wrote the Bible. Jews founded Christianity. Jews have made much in the way of scientific progress, and of course, have produced significant works of art and literature.

So, are Jews hated because of these accomplishments? How were ancient Jews the source of jealousy from others and outsiders? Why did ancient Egyptians, Bablyonians, Greeks, and Romans all want to conqure Jews, for example?

And, when and why did Jews become a race?