 The development of statistics is intimately connected on the one hand with the development of sovereign states, particularly European states following the peace of Westphalia (1648); and the other hand with the development of probability theory, which put statistics on a firm theoretical basis (see
history of probability).In early times, the meaning was restricted to information about states, particularly demographics such as population.This was later extended to include all collections of information of all types, and later still it was extended to include the analysis and interpretation of such data.