A sejmik (Polish pronunciation: [ˈsɛjmʲik], diminutive of sejm, occasionally translated as a dietine; Lithuanian: seimelis) was one of various local parliaments in the history of Poland and history of Lithuania. The first sejmiks were regional assemblies in the Kingdom of Poland (before 1572), though they gained significantly more influence in the later era of the Polish–Lithuanian Commonwealth (18th century). Sejmiks arose around the late 14th and early 15th centuries and existed until the end of the Commonwealth in 1795, following the partitions of the Commonwealth. In a limited form, some sejmiks existed in partitioned Poland (1795–1918), and later in the Second Polish Republic (1918–1939). In modern Poland, since 1999, the term has revived with the voivodeship sejmiks (sejmiki województwa), referring to the elected councils of each of the 16 voivodeships.
The competencies of sejmiks varied over time, and there were also geographical differences. Often, numerous different types of sejmiks coexisted in the same governance structure. Almost always presided over by the marshal, sejmiks could often elect delegates to the national sejm, and sometimes would give such delegates binding instructions. Sejmiks attained the peak of their importance at the turn of the 18th century, when they effectively supplanted the inefficient national sejm.
