The ruins of Zähringen castle is what remains of the ancestral seat of the Zähringer Alemannic noble family, located near Freiburg im Breisgau.

[1] The Zähringer became a powerful ducal dynasty in the area of what is now South Germany and Switzerland in the high medieval period and the founder of several cities, including Freiburg im Breisgau, Villingen, Neuenburg, Freiburg im Üechtland, Bern, Thun, Rheinfelden and Murten.

However, it is not clear without ambiguity whether they refer already to a fortification on the hilltop or to the village, the present day suburb of Freiburg.

[2] The first unambiguous mention of the castle is in the "Rotulus Sanpetrinus", a parchment roll issued in the nearby abbey of St. Peter, dated to 1128.

The castle was besieged and taken in the context of the feud between Welf VI and Conrad III by the young Frederick Barbarossa in 1146.