On 1 May 1272, archbishop Conrad II of Magdeburg created a defensive alliance with the Princes of Werle, Rugia and Mecklenburg, against the Margraves of Brandenburg.
War soon broke out between the newly elected archbishop and Margrave Otto IV, who was defeated and captured in the Battle of Frohse on 10 January 1278.
He only held the archbishop's chair for twelve years; however, this period turned out to be highly significant for the constitutional history of the city.
The citizens of Magdeburg were initially unhappy with his election, because they viewed him as the brother of the bellicose Margrave; the city had often suffered hardships during his many wars.
Several years later, Eric concluded an alliance at the Diet in Erfurt with Bishop Siegfried II of Hildesheim and other princes to maintain the public peace in the area.
The many feuds and the resultant financial difficulties gave the citizens of Magdeburg, who were struggling for greater independence, the opportunity to purchase several important privileges from the archbishop.
In a deed dated 17 January 1292, he undertook to not use the property of the cathedral chapter or to citizens of Magdeburg to pay the cost of a feud.
Thus, the city council found itself in a significantly different position: they now needed to realize their newly gained powers vis-à-vis the magistrates.
In March 1295, the city council transferred jurisdiction of real estate and inheritance cases to the Burgrave's court, allowing the magistrates to focus on criminal offences.