The history of Sieradz Voivodeship dates back to the year 1138, when following the
Testament of Bolesław III Krzywousty, Poland was divided into several smaller duchies. One of them was the Duchy of Sieradz, which until the 1260s was part of the
Duchy of Łęczyca. In 1290–1300, and after 1306, Sieradz was ruled by Duke
Wladyslaw Lokietek, who incorporated it back into the Kingdom of Poland. In 1339, Wladyslaw Lokietek created Sieradz Voivodeship out of the former Duchy. In the west, it bordered
Kalisz Voivodeship and the
Duchies of Silesia; in the north, along the
Ner river, it bordered
Łęczyca Voivodeship; in the east it bordered
Sandomierz Voivodeship along the
Pilica river from
Koniecpol to
Białobrzegi; and in the south it bordered
Kraków Voivodeship, partly along the
Liswarta river. The voivodeship had the area of 161.84 old-Polish sq. miles (= ) (1 old-Polish mile: 7,5-8.5 km), with four '''' (counties). When in 1396 the
Wieluń Land returned to Poland, it became part of Sieradz Voivodeship, which increased the area to 212.25 old-Polish sq. miles (), and the number of counties to six. In the mid-16th century, the voivodeship (without the
Wieluń Land) had 127 Roman Catholic parishes, 29 towns and 938 villages, while the Land of Wieluń had 67 parishes, 13 towns and 182 villages. Sieradz Voivodeship had five senators: the
Voivode of Sieradz, the
Castellan of Sieradz, and the Castellans of
Rozprza,
Spycimierz and Konary. Main
starostas resided in Sieradz and
Piotrków Trybunalski, there also were starostas at Radomsko, Szadek,
Tuszyn, Klonowa, Warta and other locations. The
sejmiks at Szadek elected four deputies to the
Sejm, and two deputies to the Greater Poland Tribunal in Piotrków Trybunalski.
Wieluń Land, with the area of 50.41 old-Polish sq. miles, had its own administrative system and a senator, who was the Castellan of Wieluń. It also had its own starostas, residing at Wieluń,
Ostrzeszów,
Grabów nad Prosną, and
Bolesławiec, and elected two deputies to the Sejm, at the separate sejmiks in Wieluń. Furthermore, the Voivode of Sieradz named his deputy, who ruled the Wieluń Land. ==Administration==