What were the previous names of the Guinness Premiership?

Question

Everyone recognises the Guinness Premiership as the top-flight of English rugby union. But it hasn't always been known by this name. In fact, it's had several different guises.

Between 1987 and 1997 it was known as the Courage League, before it was turned into the Allied Dunbar Premiership for three years. It was then known as the Zurich Premiership between 2000 and 2005 before Guinness became the league's full-time sponsors.