The award of the 1999 Heineman prize, even though the citation says that it is for work on integrable models, is in fact for work done from 1966-1981 on a very specific system: the two dimensional Ising model. This work includes boundary critical phenomena, randomly layered systems, the Painlevé representation of the two point function, and the first explicit results on the Ising model in a magnetic field. All of these pieces of work had results which were unexpected at the time and all have lead to significant extensions of our knowledge of both statistical mechanics and mathematics.