Lębork  is a town on the Łeba and Okalica rivers in Middle Pomerania region, north-western Poland with some 37,000 inhabitants. Lębork is also the capital of Lębork County in Pomeranian Voivodeship since 1999, formerly in Słupsk Voivodeship (1975-1998).
In 1341 Dietrich von Altenburg, Grand Master of the Teutonic Knights, granted 100 Hufen (similar to hides) to Rutcher von Emmerich for the foundation of a town named Lewinburg (Lauenburg) with Kulm rights, presumably to secure the territory around Stolp (Słupsk). East of the city the Teutonic Order completed the Schloss Lauenburg, an Ordensburg castle, in 1363. After the Battle of Grunwald (Tannenberg) in 1410, the castle was partially destroyed. In 1440 the town joined the Prussian Confederation. The population of Lauenburg was composed for a large part of Kashubians or later Slovincians.
In 1454 after the outbreak of the Thirteen Years' War, troops from Danzig (Gdańsk) occupied Lauenburg and Bütow (Bytów); the following year they were turned over to Eric II, Duke of Pomerania, to form an alliance. Because Lauenburg remained loyal to the Prussian Confederation instead of the Teutonic Knights, King Casimir IV Jagiellon of Poland granted the town three nearby villages. Troops from Polish-allied Danzig reoccupied Lauenburg in 1459 when the mayor, Lorenz Senftopf, entered into negotiations with the Teutonic Knights. Eric replaced the Danzigers with Teutonic Knights the following year, however, when he changed sides during the war. Although the Teutonic Knights were ultimately defeated in the Thirteen Years' War, Lauenburg and Bütow passed to Eric and his Pomeranian successors as the Lauenburg and Bütow Land according to the 1466 Second Peace of Thorn.
The Protestant Reformation was introduced in Lauenburg soon after 1519. The territory passed to King Władysław IV Vasa of Poland after the 1637 death of Bogislaw XIV, Duke of Pomerania. The Counter-Reformation was largely ineffective in the Lutheran town. Lauenburg was occupied by Swedes in the Northern Wars. To gain an ally against Sweden during The Deluge, King John II Casimir of Poland gave the Lauenburg and Bütow Land to Margrave Frederick William of Brandenburg-Prussia as a hereditary fief in the 1657 Treaty of Bromberg. The Swedish troops burnt Lauenburg when they left in 1658, destroying seventy houses and the town hall. Frederick William released the town from duties for five years to allow it to rebuild. Lauenburg suffered another fire in 1682.
Lauenburg became a territory of the Kingdom of Prussia in 1701. The 1773 Treaty of Warsaw granted full sovereignty over the territory to Prussia after the First Partition of Poland. The Lauenburg and Bütow Land, renamed Lauenburg-Bütowscher Kreis, was first included in West Prussia, but was transferred to Prussian Pomerania in 1777. In 1816 after the Napoleonic Wars, Lauenburg was included in Regierungsbezirk Köslin within the Province of Pomerania.
When the Lauenburg-Bütowscher Kreis was divided in 1846, Lauenburg became the capital of Landkreis Lauenburg i. Pom., a district of Prussia. Lauenburg began to develop into an industrial city after its 1852 connection on the Prussian Eastern Railway to Danzig and Stettin (Szczecin). The town became part of the German Empire in 1871 during the unification of Germany. After most of former West Prussia was granted to the Second Polish Republic as the Polish Corridor after World War I, many German migrants resettled in and around Lauenburg. A Hochschule for teacher education was established in the city in 1933. The football club SV Sturm Lauenburg played within Gauliga Pommern.
During World War II, Lauenburg was the location of the Nazi concentration camp Lauenburg, a subcamp of the Stutthof concentration camp. The city was occupied without fighting by the Soviet Red Army on 10 March 1945. Most of the Altstadt burnt in a subsequent fire, although the Gothic Church of St. James and the castle remained intact. As Lębork, the town was placed under Polish administration according to the post-war Potsdam Agreement. Germans remaining in the town were expelled and replaced with Poles.