Complex sentence: Because of the family's Jewish ancestry, the Fränkels fled to the United States during the Nazi Party's rise to power in the early 1930s and settled in Palo Alto, California, where his father Hermann was a professor of Classics at Stanford University.
Split into simpler sentences: Because of the family's Jewish ancestry, the Fränkels fled to the United States during the Nazi Party's rise to power in the early 1930s. They settled in Palo Alto, California, where Hermann Fränkel became a professor of Classics at Stanford University.