structural:reformatting
Theophanu was empress of the Holy Roman Empire by marriage to Emperor Otto II, and regent of the Empire during the minority of their son, Emperor Otto III, from 983 until her death in 991.
She was the niece of the Byzantine Emperor John I Tzimiskes. Theophanu was known to be a forceful and capable ruler, and her status in the history of the Empire was in many ways exceptional. According to Wilson, "She became the only consort to receive the title 'co-empress', and it was envisaged she would succeed as sole ruler if Otto II died without a son."