asserts that Theophanu had a love affair with John Philagathos, a Greek monk who briefly reigned as Antipope John XVI. Otto II died suddenly on 7 December 983 at the age of 28, probably from malaria. His three-year-old son, Otto III, had already been appointed King of the Romans during a diet held on Pentecost of that year at Verona. At Christmas, Theophanu had him crowned by the Mainz archbishop Willigis at Aachen Cathedral, with herself ruling as Empress Regent on his behalf. Upon the death of Emperor Otto II, Bishop Folcmar of Utrecht released his cousin, the Bavarian duke Henry the Quarrelsome from custody. Duke Henry allied with Archbishop Warin of Cologne and seized his nephew Otto III in spring 984, while Theophanu was still in Italy in the royal palace of Pavia. Nevertheless he was forced to surrender the child to his mother, who was backed by Archbishop Willigis of Mainz and Bishop Hildebald of Worms. Regency Consolidation of power Theophanu ruled the Holy Roman Empire as regent for a span of five years, from May 985 to her death in 991, despite early opposition by the Ottonian court. In fact, many queens in the tenth century, on an account of male rulers dying early deaths, found themselves in power, creating an age of greater diversity. Her power as queen, empress and regent was based on the basis of Saxon tradition (which assigned the women an equal role in the family), Byzantine influence (which presented a model of a female counterpart to the emperor) and her mother-in-law Adelaide's legacy. Theophanu and her mother-in-law, Adelaide, are known during the empress' regency to have butted heads frequently--Adelaide of Italy is even quoted as referring to her as "that Greek empress." Theophanu's rivalry with her mother-in-law, according to historian and author Simon Maclean, is overstated. Theophanu's "Greekness" was not an overall issue. Moreover, there was a grand fascination with the culture surrounding Byzantine court in the west that slighted most criticisms to her Greek origin. Theophanu did not remain merely as an image of the Ottonian empire, but as an influence within the Holy Roman Empire. She intervened within the governing of the empire a total of seventy-six times during the reign of her husband Otto II—perhaps a foreshadowing of her regency. Her first act as regent was in securing her son, Otto III, as the heir to the Holy Roman