Théophano or Théophanu or Théophania (in Greek Θεοφανώ / Theophanô ) (v.955 † 991) was a Byzantine princess given in marriage to Otton II of the Holy roman Empire and thus empress of the Germanic Roman Holy roman Empire and one of sovereign most influential of the Moyen-âge. She reigned 11 years at the sides of Otton II and 7 years as regent of her son. One can translate his name of the Greek by “appearance of God”.

Its relationship is discussed, however it seems established today that it was the niece of Jean I {{er}} Tzimiskès by her father Constantin Sklèros (it is identified as a neptis of the emperor in the marriage contract, which can mean niece or grand-daughter) and connected with Nicéphore II Phocas by his mother Sophie Phocakaina. Its birth date with Constantinople is dubious, one estimates it at 955.

At the beginning of 972, German legation, under the direction of the archbishop of Cologne Gero, arrived at Constantinople to seek Théophano. It was thus married the April 14th 972 by the pope Jean XIII in the Saint-Pierre church of Rome and crowned the same day.

It had five children:

• Adelaide, abbess of Quedlinburg, born in November or December 977

• Sophie, abbess of Gandersheim and Essen, born in 978
• Mathilde of Saxony, last woman of Ezzo, Count Palatine of Lorraine, born in 978
• Otton III, emperor, born in June or July 980
• a binocular of Otton which died before October 8th, 980, date of the celebration of its funeral mass.

Théophano accompanied her husband in all his voyages and carried out diplomatic actions on its behalf in the capacity as empress. It is known that she did not get along well with her mother-in-law, Adélaïde of Burgundy; this was the cause of the rupture between Otton II and its mother. According to Odilon de Mercœur, abbot of Cluny, Adélaïde was very content when “this Greek” died. Adalbert of Metz describes Théophano like unpleasant and talkative. She was also criticized to have introduced luxurious ornaments and jewels in Germany. The theologist Pierre Damien even affirms that it had a love affair with Jean Philagathos, a Greek monk who became briefly the antipape Jean XVI.

Widow in spring 983, it will control the empire until her death in the name of her son, Otton III. She must initially fight against the duke of Bavaria Henri the Quarreller who claims with the supervision of Otton III and is even made give the child-emperor one moment. Of return of Italy, Théophano manages to recover his/her son and the reality of the capacity in 984.

She dies the June 15th 991 with Nimwegen (currently Nijmegen (Nimègue) in the Netherlands).