The expansiveness of the complex over a length of 820 feet (250 meters) still paints a vivid picture of the castle fortress which was once so important.
The beginnings of the Hochburg go back to 10th century. To open up a new area for settlement, people began to clear large areas of the Black Forest at this time. The pioneers in land development were often aristocratic families, who created clearing centers by building castles. The Hochburg was also constructed as this kind of clearing castle. The first mention of a lord of the castle, Dietrich of Hachberg, by name originates from 1094. Archeological findings prove that the castle of the Lords of Hachberg had been built on the southern spur of the Hornwald ridge. To the south an artificial mote separates the castle square from the main crest of the Horn forest. A ring wall directly over the mote surrounded the central area of the castle. Here a square keep towered over the residential building. To the north was an adjoining forecastle which contained domestic buildings.
In the 12th century the Hochburg passed into the possession of the Margraves of Baden. With Margrave Heinrich I of Baden, the brother of the oldest Margrave Hermann V, who continued the main line of the Baden dynasty, the side line Baden-Hachberg began. With the new lord of the castle, the castle's appearance also changed. A second keep and another ring wall were erected - both with the rusticated ashlar technique so typical of the age of the Hohenstaufens. In addition, new residential and domestic buildings were constructed in the north-east. These measures reflect the desire for representation of the new castle lords.
The margraviate already ran into financial troubles in the mid-14th century, partially due to its expansionist tendencies. In the early 15th century, Margrave Otto II of Baden-Hachberg was ultimately no longer able to maintain his dominion and sold it to Margrave Bernhard I of Baden. As a result, it became the possession of the main line of Baden.
As there was no town nearby, not only the territorial and the manorial administration, but also the military protection of the earldom were located in the administrative center of the bailiff's office of the Hochburg. Offices, artisan's workshops, granaries, barns, cellars, housing for soldiers and their families and apartments for the bailiff and the commander were erected with oppressively close proximity within the castle. This resulted in the complex – called the "Hochburg" since the 15th century – soon becoming the largest in the entire Breisgau region. In times of war, the castle could house up to 350 soldiers, with the "barbier" being responsible for their health.
During the Peasants' Wars in 1525 the castle proved its defensibility by withstanding the assault of the insurgents. Following the peace treaty with the peasants, the up to that point most extensive phase of building activity began in 1533 under Margrave Karl II. The medieval aristocratic castle was converted to a castle and fortress complex in the style of the Renaissance.
His son Margrave Georg Friedrich continued the expansion work. In accordance with the latest findings of fortress architecture at that time, he surrounded the castle complex with the fortress belt consisting of seven bastions which are still clearly visible to this day. These originally 30 to 40-foot (9 to 12-meter) high defense systems are firmly anchored in the rocky ground and interconnected with passageways which are still passable today.
In the Thirty Years' War the fortress complex was besieged by the imperial troops beginning in 1634 and was ultimately captured, plundered and destroyed in 1636. What had been built at immense cost from 1598 to 1611 was torn down and transported away.
In 1660, twelve years after the conclusion of peace, Margrave Friedrich VI began with rebuilding, however the grand age of the castle complex had past. The upper castle fell victim to a major blaze caused by the careless use of fire in 1684. When Friedrich VII finally faced the French troops completely alone in the course of the War of Palatinate Succession in 1689, the castle was once again destroyed – this time once and for all.
Initial restoration measures began in the 19th century, when interest in the Middle Ages and its ruins was awakened in the Romantic age. In the 1870's and 1880's the Grand Duchy of Baden ordered urgently necessary protective measures to be taken on the castle, which was in danger of collapsing. In the early 20th century additional work for the preservation of the ruins followed until the "Association for the Preservation of the Hochburg" (Verein zur Erhaltung der Hochburg) was founded in 1971. It has been responsible for all restoration measures since that time.