Henry I of Sandomierz (Polish: Henryk) (1131 – 18 October 1166) was the duke of Sandomierz from 1138 until his death. He took part in the Second Crusade. Upon his return from the Holy Land, Henry organized a battle against the Prussians and died in battle.
The last will and testament of the Piast duke Bolesław III Wrymouth of Poland, established rules for governance of the Polish kingdom by his four surviving sons after his death. By issuing it, Bolesław planned to guarantee that his heirs would not fight among themselves, and would preserve the unity of his lands under the Piast dynasty. However, soon after his death his sons fought each other, and Poland entered a period of fragmentation lasting about 200 years.
Sandomierz Voivodeship (Polish: Województwo Sandomierskie, Latin: Palatinatus Sandomirensis) was a unit of administration and local government in Poland from the 14th century to the partitions of Poland in 1772–1795. It was part of the Lesser Poland region and the Lesser Poland Province. Originally Sandomierz Voivodeship also covered the area around Lublin, but in 1474 its three eastern counties were organized into Lublin Voivodeship. In the 16th century, it had 374 parishes, 100 towns and 2586 villages. The voivodeship was based on the Sandomierz ziemia, which earlier was the Duchy of Sandomierz. The Duchy of Sandomierz was created in 1138 by King Bolesław III Wrymouth, who in his testament divided Poland into five principalities. One of them, with the capital at Sandomierz, was assigned to Krzywousty's son, Henry of Sandomierz. Later on, with southern part of the Seniorate Province (which emerged into the Duchy of Kraków), the Duchy of Sandomierz created Lesser Poland, divided into Kraków and Sandomierz Voivodeships.
Sandomierz Voivodeship was also one of the voivodeships of Congress Poland. Created in 1816 from the Radom Department, in 1837 it was transformed into the Sandomierz Governorate.