King Casimir IV Jagiellon issued the document in Kozienice, and Łęczna was strategically located on a hill, 175 m (574 ft) above sea level.

The town, located on a busy merchant route towards Volhynia and Lithuania, quickly developed, despite Tatar raids (late 15th and early 16th centuries), and several fires (1525, 1552, 1564, 1569).

Łęczna was in private hands, with a castle, a town hall, tenement houses, churches and a synagogue.

In the mid-18th century, the town burned in two fires (1746, 1761), and in the 1760s, Łęczna belonged to Bishop of Płock, Hieronim Szeptycki.

In the 19th and early 20th century, Łęczna was a small, unimportant town, located away from main roads and railways.

During the January Uprising, clashes between Polish insurgents and Russian troops took place on 30 October, 10 November and 25 December 1863 and 4 May 1864.

In the Invasion of Poland, Łęczna was briefly captured by the Red Army (late September 1939), and then handed over by them to Nazi Germany (see Molotov–Ribbentrop Pact).

[4][5] During the second half of the second millennia Łęczna became an important Jewish center in Central Europe, hosting the Council of Four Lands for several times.

In January 1940, a local Judenrat was established in order to organize the Jewish life in Łęczna under Nazi restrictions.

Furthermore, there are forests rich in birds and animals, and Polesie National Park lies a few kilometers north of the town.