The Pharisees rose up during the Babylonian
captivity. The Israelites, during their exile, had
to be content with the dream of restoring their
temple and the Book of the Law that they took
with them.

The Law became the center of the Jewish life.
When they returned from captivity and the
temple was rebuilt, they restored the old
priestly order. The Law didn't cease to be the
center of the nation.