Complex sentence: The purpose of Kings Rooty Hill settlement was to provide a reserve for government-owned cattle and the south-western part of this vast area (which closely follows Blacktown City's current boundary) came to be known as the Rooty Hill Run.
Split into simpler sentences: The purpose of Kings Rooty Hill settlement was to provide a reserve for government-owned cattle. The south-western part of this vast area (which closely follows Blacktown City's current boundary) came to be known as the Rooty Hill Run.