Friedrich von Isenberg

Count Frederick of Isenberg (Friedrich von Isenberg) (1193 – 15 November 1226) was a German noble, the younger son of Count Arnold of Altena (died 1209). His family castle was the Isenburg near Hattingen, Germany.

According to recent research, Frederick of Isenberg was a leading figure in the opposition of Westphalian nobles to the aggressive power politics of the Archbishop of Cologne, Engelbert of Berg.

In 1225 at the Nobles' Assembly in Soest, Count Frederick met his cousin Count Engelbert von Berg, Archbishop of Cologne, in order to bring about a peaceful agreement concerning the stewardship (Vogtei) of Essen Abbey, which Count Frederick, according to contemporary complaints, was abusing to his own benefit and to the detriment of the abbey. No conclusion was reached.

During their return together from Soest to Cologne, Count Frederick arranged to ambush his cousin, in a defile at the foot of the Gevelsberg between Hagen and Schwelm in the late afternoon of 7 November 1225, in the course of which the Archbishop was killed.

There is no consensus as to whether it was a deliberately planned murder, or whether the Archbishop was killed in the heat of combat. Current research assumes the latter, and that it was intended to take him into "knightly detention" so that the political demands of the opposing nobility could be pushed through. This was in accordance with the customs of the medieval feuding ethos.

Frederick of Isenberg was outlawed and excommunicated. He was stripped of all offices and stewardships and his entire personal wealth. In the winter of 1225/1226 the new Archbishop of Cologne, Heinrich von Müllenark, besieged and destroyed his castle.

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