Union of Lublin
Prior to the 1569 Union of Lublin, Crown territories may be understood as those of the Kingdom of Poland proper, inhabited by Poles, or other areas under the sovereignty of the Polish king (such as Royal Prussia) or the szlachta. With the Union of Lublin, however, most of the present-day Ukraine (which had a negligible Polish population and had until then been governed by the Lithuania), passed onto Polish administration, thus becoming Crown territory.