The current fourth tier of the Polish national league system was established on 19 February 2000, under the name
IV liga. Previously, the fourth tier of competition was held under many different names depending on the region, including
macro-regional league,
macro-regional class,
inter-voivodeship league,
district league, among others. In August 2000, the first official season of new fourth tier commenced with teams spread across 21 territorial groups. In five voivodeships (Lower Silesia, Lesser Poland, Masovia, Silesia and Greater Poland), the competition was divided into two groups, the winners of which met in a two-legged play-off for the championship and promotion to the third tier. In the remaining 11 voivodeships, only one group was held, the winner of which automatically earning promoted to a higher division. In subsequent editions, the number of groups was gradually reduced and the number of teams in each of them was limited. In 2001, both Lower Silesian groups were merged, in 2002 - the Masovian ones, and in 2006, the Lesser Poland groups. In 2007, the fourth tier consisted of 18 regional groups. In 14 voivodeships, the games were played with a single-group system, and in two voivodeships, with a two-group system. Starting from the 2008–09 season, the league was renamed to
III liga, and reduced to 8 groups. The winners of each group (in the case of voivodeships with two groups, the winners of the play-offs between the winners of both groups) formed four play-off pairs, winners of which were promoted to the
II liga. The latest restructure came in effect ahead of the 2016–17 season, with the numbers of teams reduced to 72 across four groups. ==Current format==