Simplify the following text for a Grade 12 native English-speaking person.
Original: Relying heavily on substantial financial support from businessman Brooks Mileson , the club were promoted through the Scottish leagues from the Third Division to the Scottish Premier League in less than five years .
Simplified: Under the ownership of businessman Brooks Mileson , who invested millions of pounds in what was a village team , the club went from the Third Division side to the Scottish Premier League ( SPL ) in less than five years .