History: The construction of a landgrave's castle on the western edge of today's town can be seen as the nucleus of urban development. There are no archaeological finds or historical sources that prove previous settlement at this location. Today's Runneburg was the main castle and today's old town of Weissensee can be described as the outer bailey. The latter only received its own municipal rights after the Landgraves of Thuringia died out, while the main castle remained in sovereign ownership. From 1168 onwards, Countess Jutta Claricia of Thuringia, a half-sister of Emperor Frederick Barbarossa, had the castle in Weissensee expanded into a residence for the Landgraves of Thuringia. The town and the castle were first mentioned as "Wyssense" in 1174 in a document by Landgrave Ludwig III, the Pious of Thuringia. Weissensee came into the spotlight of German history in 1180, when Henry the Lion defeated the Thuringian Landgrave Ludwig III in the Battle of Weissensee. and defeated his knights. During this period, Weißensee already had a mint. After the Hessian-Thuringian War of Succession, the Thuringian regions and thus also Weißensee fell to Margrave Henry III of Meissen. In 1198, market rights were granted and in 1265, town rights. The Wettin margraves often and regularly stayed in the castle and in the town. In 1382, Weißensee came back into Thuringian possession. In May 1440, the last Landgrave of Thuringia, Frederick IV, the Peaceful, died in the castle at Weißensee, which then came into the possession of the Dukes of Saxony. During the division of Leipzig in 1485, the town, the castle and the Weißensee office passed to the Albertine line of the Wettins. During the Peasants' War in 1525, the rebellious peasants were denied entry to the town and the castle. From 1656 to 1746, Weissensee, the castle and the office of the same name belonged to the Duchy of Saxe-Weissenfels. During this time, when the actual landgrave history of the castle and town had been forgotten, the embarrassing name "Runneburg" (round castle) was used for the first time in documents. After the Congress of Vienna, the town and castle came to the Kingdom of Prussia in 1815. The town became the administrative seat for the Prussian district of Weissensee in the Erfurt administrative district of the Province of Saxony. The lakes that previously existed in the area (Obersee and Niedersee) played an important role for the nobility and the town. In both the Niedersee and the Obersee, duck hunting took place every 14 days in the autumn together with the citizens. When duck hunting was no longer profitable, the Duke drained the Obersee in 1709. From 1788 to 1796, the Niedersee was also converted into arable land. Due to the good fertility of the areas thus acquired, good agricultural yields could be achieved. In 1434, a regulation called Statuta thaberna (tavern law) was drawn up in the then Landgrave town. The twelfth article stipulated, among other things, that only hops, malt and water were to be used for brewing. In the event of a violation, a fine of two marks and a four-week ban on entering the town were threatened. Due to its similarity to the later Bavarian Purity Law, this document is also known as the Weissenseer Purity Law. It was found in 1998 in the historical part of the town archives during preparations for the 800th anniversary of the Weissenseer market law.