In world will be small enough to

In the tenth century, the highest position a woman could fill was that of queen, and even that was dependent on a man- a woman could only be a queen if she married a king. However, this does not mean that the queen had no power. She played an important role in advising the king, as can be seen on looking at the diplomata (royal acts) of the time, which often say that a grant had been made at the intercession of an individual: queens were the most frequent intercessors.She was also in charge of the royal household and the education of the heir to the throne, but, most importantly, she could act as a regent if her husband died and the heir was not of age. "Her role was often transformed from that of partner or co-adjutant to that of guarantor of dynastic continuity, managing the politics of succession and/or acting as regent for her minor son."
In 983 in Ottonian Germany, when Otto II died leaving a three year old son (Otto III) as his heir, this situation occurred. The regency was to be shared between his wife, Theophano, his mother, Adelheid, and his aunt, Mathilda. Only two of these women ruled actively: Theophano, from 983 to her death in 991, and Adelheid, from 991 to Otto's coming of majority in 998. They were constant rivals, perhaps because there could only really be one queen and they saw each other as threats. In 991, Theophano is even supposed to have said "if I live another year, Adelheid's power in this world will be small enough to fit in the palm of my hand". Ironically, she didn't, dying less than a month later. As they both had periods of sole regency, it is possible to compare their reigns and see who was the most successful, in terms of experience, diplomacy and foreign policy, maintenance of the peace, and relationship with the clergy.
Theophano and Adelheid both had experience with ruling before their regencies. They both had knowledge of the workings of the court system from…