A church was built in 1366, and in 1498 Polish prince and Primate of Poland Frederick Jagiellon founded a hospital for the poor.

[3] In 1422 it was granted town rights modeled on Środa Śląska by virtue of a document issued by Polish king Władysław II Jagiełło in Mielno.

[4] Crafts soon developed and in 1517–1523, the town's landmark Gothic collegiate church was erected under the patronage of the Primate of Poland Jan Łaski.

From that time forward, the Jewish population of the town averaged between 50% and 65% of the total, typical of small shtetls of the region.

[2] At the same time, Łask saw an influx of Jewish people fleeing persecution in Russia (see Pale of Settlement).

"[7] With the invasion of Poland and the outbreak of the Second World War in September 1939, Łask was occupied by the Wehrmacht and annexed by Nazi Germany.

The town was then administered as part of the county or district (kreis) of Lask within the newly formed province Reichsgau Wartheland, and the Jewish half of the population and the Polish intelligentsia were systematically targeted and annihilated under the racial policy of Nazi Germany.

The town's synagogue was then surrounded by the Nazis and "hundreds more" Jews were shot and killed as they tried to defend the building.

[12] Following the arrival of the Red Army and the subsequent end of the war in 1945, Łask became part of the People's Republic of Poland.