Just as scientists and engineers, statisticians rely upon mathematical models. While for the scientist or engineer differential equations is commonly the area of mathematics of most utility, and while these tools are not unimportant for the statistician, the statistician's primary mathematical tool is probability. Some facts from probability of most value to the area of statistics have only been established in the last hundred years or so. Whether they are considered results from probability or from statistics and whether their authors are considered statisticians or probabilists, the application of these facts has been primarily important to the practice of statistics. In many cases the results were motivated by statistical problems.
More historical information is available.