Mergentheim is mentioned in chronicles as early as 1058, as the residence of the family of the counts of
Hohenlohe. The brothers Andreas, Heinrich and Friedrich von Hohenlohe joined the
Deutscher Orden (
Teutonic Order) in 1219 and gave their two castles near Mergentheim to the order. One was abandoned, the other became the seat of the local
Komtur (commander) of the order. Following the Order's conquest of
East Prussia and part of
Livland in the 1230s, in 1309 the Grand Master of the order moved to the
Marienburg. In 1340 Mergentheim was awarded
town privileges. It rapidly became the most important of the eleven commanderies of the Teutonic Order. The
Deutschmeister, highest ranking member inside the
Holy Roman Empire (to which Prussia did not belong), moved his seat to Mergentheim in 1525 after his castle at
Hornberg/Neckar had been
destroyed by peasants. That same year, Grand Master
Albrecht von Zollern-Brandenburg resigned his position, left the order, introduced
Reformation, married and – supported by his liege lord the
King of Poland – turned the order's eastern territories into a temporal duchy. The rulers of the order in Germany, now styling themselves
Hoch- und Deutschmeister, then made Mergentheim the order's new headquarters and expanded the castle into a palatial residence. Over the next centuries, the town served as the centre of the order's southern German territories much like the residence town of any ruling prince. Some grand masters, like
Archduke Leopold Wilhelm of Austria (1614–62), who in his 21 years in that role never once set foot in the town, were hardly ever present. Others, like
Maximilian Franz (1756-1801), a son of
Maria Theresa, loved the place. For the order's general chapter in 1791 he brought the orchestra of the
Archbishopric of Cologne, including one
Ludwig van Beethoven on viola. Mergentheim retained this role until the dissolution of the order in the countries of the
Rheinbund in 1809 by
Napoleon. Mergentheim's fortunes declined after that but were reversed in 1826, when a shepherd by the name of Franz Gehring discovered rich mineral springs in the surrounding area, during the time when spas were expanding in Germany at a rapid pace. The water turned out to be the strongest
sodium-sulfate water in Europe, reportedly effective for the treatment of digestive disorders. In the 1970s during the
Gemeindereform (administrative reform) several neighbouring villages were incorporated into the municipality. ==Arts and culture==