Coup of Kaiserswerth

The Coup of Kaiserswerth (German: Staatsstreich von Kaiserswerth) in 1062 was a hitherto unprecedented action of several secular and ecclesiastical Princes of the Holy Roman Empire under the leadership of Archbishop Anno II of Cologne against Empress Agnes, ruling on behalf of her under-age son, King Henry IV, and against her chosen sub-regent, Bishop Henry II of Augsburg. By kidnapping the young king and enforcing the handover of the Imperial Regalia, the group gained control of the reins of power in the Empire.

In early April 1062, eleven-year-old Henry IV and his mother were staying in the Königspfalz of Kaiserswerth (today a quarter in Düsseldorf), erected by Agnes' late husband Emperor Henry III, where both met with Archbishop Anno II of Cologne. After banqueting together, Anno invited the boy to visit a magnificent ship that he had moored in the River Rhine nearby. What Henry experienced when he boarded the ship, is related by the contemporary chronicler Lambert of Hersfeld as follows:

But no sooner had he entered the ship when he was surrounded by the archbishop's hired accomplices, the rowers quickly gathered themselves up, threw themselves behind their oars with all their might and propelled the ship rapidly into the middle of the stream. The king, stunned by these unexpected events and unsure what was happening, could only think that they wanted to attack and murder him, and so plunged headlong into the river, and he would have drowned in the raging waters had not Count Egbert, despite the great danger in which he put himself, dived in after him, and rescued the endangered king from drowning with great difficulty and returned to the ship.

Anno then took the king up the river to his Cologne residence and blackmailed Empress Agnes to hand over the Imperial Regalia. As a consequence the power of the state fell into the hands of the rebels, who, in addition to Anno and Count Egbert of Brunswick, mentioned by Lambert, also included Otto of Northeim as well as the Archbishops Adalbert of Bremen and Siegfried of Mainz.

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