Who was the bookie, cricketers & nations that were involved in most shameful match fixing of the 20th century?

EDIT: No offence friends most nations were involved, just wanted to know how it all started..i.e., what motivated the whole thing to unravel? Folks the chronology of events or reference will be greatly appreciated MGN, Azhar was also one of my favourites till all this happened! A very elegant playe...