Theophanu

Theophanu Skleraina (German pronunciation: [te.o.fa.ˈnuː]; also Theophania, Theophana, Theophane or Theophano; Greek: Θεοφανώ, romanized: Theofanó; c. 955 – 15 June 991) 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. Her official titles contained 'consors imperii', which her stepmother Adelaide of Italy already received and 'comperatrix augusta', which was modeled after the Byzantine position of the empress to ensure succession and regencies.

Source: Wikipedia — https://en.wikipedia.org/wiki/Theophanu