The Erbreichsplan was a plan formed by the Emperor Henry VI to change the Holy Roman Empire from an elective to a hereditary monarchy. Such a move would have drastically changed the character of the Empire, but Henry was unable to garner sufficient support for the plan and it was ultimately forgotten.
Background
Henry, who had been crowned Holy Roman Emperor in 1191, was known for being highly aggressive in guarding and expanding the rights of the imperial crown. In 1194 he also invaded the Kingdom of Sicily and conquered it from its king, William III. That same year his wife Constance gave birth to a son, Frederick II, who would, if all went well, inherit both the Imperial title and the Kingdom of Sicily. It was Henry's dream to have the Empire and Sicily permanently unified under the House of Hohenstaufen. Unfortunately for Henry's plans, however, the Empire was an elective monarchy, meaning that the Hohenstaufens' hold on the imperial title depended on a favorable election by the princesafter the death of every Emperor. The dynasty's hold on the empire could never be secure as long as the princes controlled the electoral process. Henry was aware of developments in other European countries such as France, where the principle of hereditary monarchy was firmly established and the strength of the crown was increasing. Henry ultimately decided on pursuing a way to change the imperial title into a hereditary one, and attempted to gain the support of the princes of the Empire. The secular princes, for their part, feared Henry's extensive powers. Although hereditary succession for princes had become customary within the Empire, it was still not a formal right and on multiple occasions Henry refused to enfeoff the direct heir of a deceased prince with the latter's territory. As a result, the princes were nervous about their rights of inheritance and were willing to grant certain concessions to the Emperor in exchange for the preservation of these rights.
The Plan
After his capture of Sicily in 1194 Henry was busy organizing for a possible crusade and negotiating over the election of his son Frederick as his successor within the Empire. The secular princes in the meantime made their desire for hereditary imperial fiefs, and for the recognition of the capacity for inheritance by the female line as well, known. By agreeing to consider these demands Henry was able to gain the acceptance by a majority of the secular princes for the idea of hereditary monarchy. Henry also bought the support of the ecclesiastical princes by announcing that he would be willing to give upthe right of jus spolii, which had for years been used against Church lands. Despite the high degree of support he had from the secular and ecclesiastical princes for the idea, however, Henry was unable to secure an agreement in writing. The first obstacle to the plan was the Archbishop of Cologne, Adolf of Altena. Besides being opposed towards Henry's rule in general, Adolf was unwilling to give up the significant level of influence that his position traditionally held over the imperial election. When he aroused the resistance of several Saxon and Thuringian princes against the Emperor, Henry realized that he would be unable to establish hereditary monarchy without resistance. Henry next turned to the papacy, hoping that if he could get the support of the pope that the matter would be settled. Pope Celestine III, however, had many reasons to oppose such a plan, including the classic papal opposition to the expansion of Imperial power in Italy. Henry tried to compromise with Celestine, offering to meet several papal demands and probably offering a financial incentive. Ultimately the pope decided that the hazards of a hereditary monarchy were too great and refused to support Henry. Henry now found his campaign to turn his office into a hereditary one stalled. He gave up on his plans for the time being, in the meantime securing the election of Frederick as King of the Romans in late 1196. Over the next year he was bogged down by a revolt in Sicily and preparations for the Crusade, when he suddenly died in September 1197. His death put a definitive end to his plans for hereditary Imperial succession; the issue was quickly forgotten as the Empire quickly descended into civil war between Philip of Swabia and Otto IV. Henry's attempts to turn the Imperial title into a hereditary one were ultimately futile, and the Holy Roman Empire remained an elective monarchy all the way up until its dissolution in 1806.
