Complex sentence: During the early part of the Zhou Dynasty period, royal relatives and generals had been given control over fiefdoms in an effort to maintain Zhou authority over vast territory, many of these broke up into smaller states when the dynasty weakened.
Split into simpler sentences: During the early part of the Zhou Dynasty period, royal relatives and generals had been given control over fiefdoms in an effort to maintain Zhou authority over vast territory. Many of these broke up into smaller states when the dynasty weakened.