Engelbert’s power had gone. He could not even stop himself from being imprisoned for twenty days by the citizens for supposedly hatching an armed plot against the patricians. The pope, Urban IV, more and more concerned by the city’s efforts to achieve independence, attempted to intervene several times, despite his low opinion of Engelbert. The latter tried everything, including stirring up the guilds, who were defeated by the patricians in a bloody conflict. At last the ensuing arbitration made the patricians go barefoot to beg the archbishop’s forgiveness once again. Under Conrad that had been the beginning of a nightmare for them; under Engelbert it led to farce. The archbishop again tried to subdue Cologne by force of arms and instigated an intrigue that was a complete failure, compelling him to flee to Bonn. There was the usual reconciliation, but while outwardly Engelbert was all sweetness and light, in secret he was stirring up the old antipathies between the noble families, inciting the Weises against the Overstolzes. At the last moment open conflict was avoided through the mediation of Count William of Jülich, the old enemy of Conrad and of the archbishops in general. Engelbert then took up arms against William, devastated his territory, and spent the next three and a half years imprisoned in Jülich.
In the meantime William’s efforts were proving vain—the Weises and the Overstolzes were at each other’s throats. Ludwig Weise, the burgomaster, and Matthias Overstolz came to blows. Weise was killed and the rest of the family sought asylum with the Church. Only the hasty arrival of William of Jülich stopped the Overstolzes from wiping out the Weises. The latter were expelled from the city and the Overstolzes took over.
Time for a new intrigue. Engelbert, lord of the city on paper alone, formed an alliance with the Weises and the tradesmen. Money was spent and a tunnel was dug under the city walls through which the Weises intended to return. This plan also came to naught. Although the Weises entered the town, they were driven out again in a bloody battle. Among the dead was Matthias Overstolz.
In 1271 Engelbert returned from imprisonment. A changed man, he made peace with the city. Three years later he died.