The nearby lake was economically important to the town as the fertile soil of the area. The establishment of a Landgrave Castle on the western edge of today's city can be considered as the nucleus of urban development.
There are no archaeological findings and historical sources, supporting a previous settlement in this place. Today's Runneburg was the main castle and the Old Town Weißensee can be described today as bailey. The latter was given only after the extinction of the Landgrave of Thuringia own municipal rights, while the main castle remained in sovereign possession. From 1168 the Ländgräfin (Countess) Jutta Claricia von Thüringen, a half-sister of Emperor Friedrich Barbarossa, made the expanded Runneburg in Weißensee a residence of the Landgrave of Thuringia. The town and the castle were mentioned for the first time as "Wyssense" in 1174 in a charter of Landgrave Ludwig III, the pious of Thuringia. Weißensee becam the focus of German history in 1180, when Henry the Lion defeated his knights of Thuringian Landgrave Ludwig III at the Battle of the Weißensee. After the Hesse-Thuringia war were the Thuringian parts and thus Weißensee fell under Margrave Heinrich III von Meißen. In 1198 the market and 1265 the town were granted charter. The Wettin Margrave frequently and regularly stayed at the castle and in the town. In 1382 Weißensee came into the possession of Thuringia. In May 1440, the last Landgrave of Thuringia, Friedrich IV died, the peaceful Runneburg and Weißensee, were then in the possession of the Dukes of Saxony. During the Peasants' War in 1525 the rebellious peasants of the inlet were denied into the town and the castle. From 1656 to 1746 and Weißensee and Runneburg belonged to the Duchy of Saxe-Weißenfels. After the Congress of Vienna in 1815, to town and castle were in the Kingdom of Prussia. The town was the administrative seat of the Prussian district of Weißensee.
In 1434 a Statuta thaberna (Tavern Act) Regulation was written in the former Landgrave town. Their 12th article laid down, inter alia, that at the eyebrows, only hops, malt and water are used. In the case of the infringement on entering the town to be threatened penalty of two marks and a four-week ban. Because of its similarity to the later Bavarian purity law that document is also known as Weißenseer purity. Iin 1998 when the preparations for the 800th Anniversary of Weißenseer market right it was found in the historic part of the town archive, which is located in the medieval Runneburg after it had been deposited for decades at the site of the country's main archive Wernigerode Saxony-Anhalt.
In the era of National Socialism from 1937 to 1944, 181 women and men were victims of forced sterilization in the then Weißensee district. The victims came from Weißensee, Waltersdorf, Scherndorf, Gangloffsömmern, Großrudestedt, Günstedt and Riethnordhausen. During World War II more than 500 prisoners of war from Poland, France, Croatia, Serbia and Russia as well as women and men from these countries and Slovakia, the Netherlands and Ukraine, had to perform forced labor at the Rheinmetall Borsig AG, where improvement works on the Stadtgut Luthersborn and the Weißenburg property, the Counts of Werthern'schen Schönstedt estate administration and the Ottenhausen manor. Three women were publicly banned for dealing with prisoners in the marketplace, shaved and then deported to the Ravensbrück concentration camp
Ludwig II, the Iron (1128-1172), Landgrave of Thuringia from 1140 to 1172
Jutta Claricia von Thüringen (c1133/1134-1191), Countess
Ludwig III, called the Pious or the Mild (1151/1152-1190), Landgrave of Thuringia from 1172 to 1190
Friedrich IV, the Peaceful (1385-1440), Landgrave of Thuringia
Heinrich Hetzbold von Weißensee (14th century), minstrel
Johann Ernst Gründler (1677-1720), German missionary
Johann Christian von Schreber (1739-1810), physician and naturalist
Johann Jakob Leitzmann (1798-1877), pastor and numismatist, numismatic publisher of the first German newspaper from 1834 to 1873
Otto Posse (1847-1921), archivist and historian
Johannes Görbing (1877-1946), chemist, soil scientists and agriculture physiology
Oskar Brüsewitz (1929-1976), evangelical pastor
Peter Albach (b 1956), politician (CDU), MP
Hans-Ludwig Grabowski (b 1961), numismatist and writer