The starting and ending dates of the polity. For example, the starting date could be the establishment of a long-ruling dynasty, while the ending date may be the year when the polity was conquered by an aggressive neighbor. In cases when starting and/or ending dates are fuzzy, as explained above, use the earliest possible starting date and the latest possible ending date. This approach will result in a temporal overlap, so that some NGAs for some periods will be coded as belonging to two polities simultaneously (e.g., to a disintegrating overarching polity and to the rising regional subpolity). Such overlap is acceptable, and will be dealt with at the analysis stage.