Łęczyca is one of the oldest Polish cities, mentioned in the 12th century. It was the place of the first recorded meeting of Sejm, the Polish parliament, in 1182. In 1229, during the period of fragmentation of Poland, it became the capital of the Duchy of Łęczyca, which in 1263 was split into two parts - the Duchy of Łęczyca and the Duchy of Sieradz. In the early 14th century, the Łęczyca Voivodeship was created with Łęczyca serving as its capital. This administrative unit of the Kingdom of Poland was part of the larger Greater Poland Province of the Polish Crown and existed until the Partitions of Poland in the late 18th century. It was a royal city of the Polish Crown.