Empire. Theophanu also placed her daughters in power by giving them high positions in influential nunneries all around the Ottonian-ruled west, securing power for all her children. She welcomed ambassadors, declaring herself "imperator" or "imperatrix", as did her relative contemporaries Irene of Athens and Theodora; the starting date for her reign being 972, the year of her marriage to the late Otto II. Theophanu's regency is a time of considerable peace, as the years 985-991 passed without major crises. Internal peace, diplomacy, warfare and cultural achievements In the North, she made a treaty with King Erich VII of the Danes (Seghersell), which promoted an alliance against Slavic tribes as well as reinforced trade and cultural connections. In the East, she sent envoys to Vladimir the Great of Kiev, who was married to the Byzantine princess Anna, (sister of Emperor Basil II. Economou notes that, "Theophano had in mind a 'family of kings,' in parallel to Byzantine tradition: The emperor was the 'father' of other kings, who were his 'sons' and 'friends' (amici) in a kind of family hierarchy. She also adopted the Byzantine model of relations between the emperor and patriarch in her relations to the pope (Ostrogorsky 1956b). The 'family' of the western empire included the duke of Poland, Mieszko I, Bohemia and Hungary". Her model of imperial rulership, influenced by Byzantine and Ancient Roman ideas, was taken over by Otto II and especially Otto III who developed it further (although his abrupt death at a very young age prevented it from becoming an established foundation for the future). According to historian Gerd Althoff, Theophanu's prowess in diplomacy could be exaggerated. Royal charters present evidence that magnates were at the core of governing the empire. Althoff highlights this as unusual, since kings or emperors in the middle ages rarely shared such a large beacon of empirical power with nobility. Theophanu introduced Byzantine protocol, "which influenced dress, crowns and jewelry, eating habits and utensils, even furniture". Her retinue of scholars brought to the Empire Byzantine lawyers' procedures. The cult of Saint Nicholas in the Empire traces its origin from her too. As she and her husband and her son promoted trade in the Empire, Magdeburg and its traders were granted various privileges. Historical evidences show strong commercial activities in regions from Lüneburg to Halle. There are traces of Byzantine, Slavic as well as Arab traders. As with many Byzantine regents,