Complex sentence: But the young man, by his violent and oppressive rule, soon alienated the minds of the citizens, who in consequence applied for relief to Hieron of Syracuse, at that time on terms of hostility with Theron.
Split into simpler sentences: But the young man, by his violent and oppressive rule, soon alienated the minds of the citizens. They applied for relief to Hieron of Syracuse, at that time on terms of hostility with Theron.