Already in 1091 the duke Berthold II of Zähringen ordered the construction of the Castrum de Friburch on the Schlossberg (castle hill) of Freiburg in beautiful Romanesque style.

The Duke's servants and craftsmen lived at the foot of the mountain in the area of what today is the southern part of the historic center, but it was only in 1120 when his son Konrad, with the approval of emperor Henry IV, granted the settlement market rights, thus ending the startup phase of Freiburg.

The existence of the castle is proved at least since 1146 when Bernhard of Clairvaux described in his travel diaries how he healed a blind boy apud castrum Frieburg (at the fort Freiburg).

In the war against their ruler count Egino II and his brother-in-law, the bishop of Strasbourg Konrad von Lichtenberg, in 1299 they used catapults against the castle for the purpose of blowing a breach.

Later emperor Leopold I built a mountain fortification including the motte-and-bailey castle in 1668, the "Leopoldsburg", as a bulwark in defense of the threat to the Breisgau imposed by Louis XIV of France.

[2] In the War of the Spanish Succession, the fortress occupied with a strong Austrian garrison was beleaguered and taken again by French troops under Marshal Louis Hector de Villars.

However, before the French left the city they destroyed Vauban's fortifications practically completely so that of the former castle (whose main component was a donjon shown on illustrations) only a debris cone and the neck ditch remained.