The place name 'Gundolfsheim' was first mentioned in 767 AD and probably derived from a person's name.
In about 1250 Konrad of Horneck and his sons joined the Teutonic Knights and donated the fortress as a pious foundation. From then it was devoted to the Teutonic Order for hundreds of years. In 1438 the fortress became the seat of the Grand Master of the Teutonic Order. The town that developed below the fort, Gundelsheim, received its town and market charters in the 14th century.
After the destruction of the fort in the Peasants' War in 1525, the Grand Master of the Teutonic Order had to move his seat to Mergentheim. Horneck was rebuilt as a renaissance palace. In 1646 the castle and town were besieged and stormed by the Swedes. Between 1688 and 1815, during the Wars of Succession and the Napoleonic Wars, it experienced devastation at the hands of troops marching through it. In 1805 the castle and town became part of Württemberg. From 1891 until 1939 it became the location of a renowned sanatorium, which became a vital economic factor for local trade and industry. Since 1960 Horneck Castle has been a meeting place for the Siebenbürger Saxons and Gundelsheim their cultural centre in Germany.
A tradition of wine-growing on the steep slopes of Michaelsberg, the 'Kingdom of Heaven' (Himmelsreich), together with the eye-catching town, the sublime Horneck Castle, as well as the old town with cosy lanes and lovely half-timbered houses make up the unmistakeable scenic backdrop of the town.