Plön (; Holsatian: Plöön) is the district seat of the Plön district in Schleswig-Holstein, Germany, and has about 8,700 inhabitants. It lies right on the shores of Schleswig-Holstein's biggest lake, the Great Plön Lake, as well as on several smaller lakes, touching the town on virtually all sides. The town's landmark is Plön Castle, a chateau built in the 17th century on a hill overlooking the town.
Plön has a grammar school with a 300-year history, and is home to a German Navy non-commissioned officer school and the Max Planck Institute for Evolutionary Biology. The town, nestled as it is in the hilly, wooded lake district of Holstein Switzerland (Holsteinische Schweiz), also has importance in the tourism industry.
History
In the course of the Migration Period, Slavic tribes entered the region of Plön during the early 7th century following the withdrawal of the original Germanic population. On the large island opposite Plön, which was later called Olsborg, they built a large fortification. They called their settlement Plune, which means "ice-free water".
In 1075, Kruto lured Budivoj of the Nakonids into the "castrum plunense" (according to Helmold of Bosau), laid siege to him, and then once Budivoj's men had given themselves up after Kruto's promises to let them withdraw freely, Kruto had them slain. In 1139 the Count of Holstein, Adolf II of Schauenburg, destroyed the fortress, ending the domination of the Slavs in the region of Plön. Twenty years later, Adolf II had the castle on the island rebuilt, but soon had it moved to the present hill of Schlossberg ("castle hill"). It was here, under the protection of the castle and close to the major trading route from Lübeck to the north, that a Saxon market town emerged.
In 1236, Plön was granted town rights under Lübeck law. Strategically located on a narrow isthmus between the lakes and the River Schwentine, Plön remained a centre of the County of Holstein until the Danish royal house fell in the 15th century.
Between 1561 and 1729, Plön was the capital of the Duchy of Schleswig-Holstein-Sonderburg-Plön. The Duchy of Schleswig-Holstein-Plön emerged in 1622 as a result of succession in the Danish royal house. From 1633 to 1636 a Renaissance castle was built on the site of the old castle by Duke Joachim Ernest, and Plön became the capital of the small but independent princedom. As a residence town Plön experienced a considerable increase in status. For example, in 1685 Duke John Adolphus ("Hans Adolf") founded the new town (Neustadt) northwest of the town in order to settle craftsmen here and thus increase the economic might of the duchy. Under Charles Frederick the castle district was expanded with several baroque buildings and a pleasure garden. At that time the town had about 1,000 inhabitants and reached as far as the bridge over the Schwentine in the east and as far as the end of today's pedestrian zone in the west. Both entrances were protected by gates.
In 1761 the Duchy fell back into the hands of the Danish crown. Plön remained under Danish rule until the Second Schleswig War in 1864. Although it was the Danish king's summer residence from time to time, it remained otherwise a sleepy provincial town of about 2,000 inhabitants. The cultural life of the minor residence was charmingly described by Rochus von Liliencron in his "Childhood Memories". In the mid-19th century, the Danish crown prince spent a few years of his summer vacation in Plön Castle, since when it has been decorated in white plaster with a gray roof.
In 1867 Plön became a county town following the introduction of Prussian administrative reforms. The Hohenzollern princes were educated for a time in Plön. The Princes' Island (Prinzeninsel) is still owned by the House of Hohenzollern. Since 1868, Plön Castle was a Prussian military school. After World War I it became a boarding school that served as a 1933-1945 as a National Political Institutes of Education. Since 1946, it has again been a state boarding school. After the end of World War II, former NAPOLA pupils were often able to avail themselves of a form of ‘evasive selective memory’ that ultimately cast themselves as victims of the Nazi regime, and allowed them to make their own (sometimes very successful) way in postwar society. During the War, numerous forced laborers lived in Plön and the surrounding area. In the Plön cemetery, eight wooden crosses commemorate people who were probably forced laborers from Eastern Europe. According to a police report, forced laborers who were no longer able to work allegedly 'drowned while going swimming' in the Plöner See.