Simplify the following text for a Grade 9 native English-speaking person.
Original: The county within which the sheriff exercises his jurisdiction is still called his bailiwick , while the term bailiff is retained as a title by the chief magistrates of various towns and the keepers of royal castles , such as the High Bailiff of Westminster , the Bailiff of Dover Castle , etc. .
Simplified: The sheriff looked after an area called his bailiwick . Bailiff is kept as a title by the chief magistrates of various towns and the keepers of royal castles , such as the High Bailiff of Westminster , and the Bailiff of Dover Castle .