At the IAU General assembly in Prague in August 2006 a resolution was passed to define a class of Dwarf Planets and to reclassify Pluto as the prototype of this new class of objects. This event received a high level of attention, in the public, and in the astronomy and the planetary communities. I will give some of the background to the IAU decision and explain why we handled it the way we did. Since 2006 we have had spirited discussions on the www etc, including the recent debate at CfA, which arrived at a naive version of the original IAU proposal!