question: What nationality is Sophia I, Abbess Of Gandersheim's mother?
context: Title: Theophanu
  Passage: Theophanu (also "TheophaniaTheophana", or "Theophano", Greek ; AD 955 15 June 990), was an Empress consort of the Holy Roman Empire by marriage to Holy Roman Emperor Otto II, and regent of the Holy Roman Empire during the minority of her son from 983 until her death in 990. She was the niece of the Byzantine Emperor John I Tzimiskes.
  Title: Sophia I, Abbess of Gandersheim
  Passage: Sophia I (September 975 – 30 January 1039), a member of the royal Ottonian dynasty, was Abbess of Gandersheim from 1002, and from 1011 also Abbess of Essen. The daughter of Emperor Otto II and his consort Theophanu, she was an important kingmaker in medieval Germany.
answer: Roman Empire
citations: Theophanu Sophia I, Abbess of Gandersheim