Theophanu in the context of "Holy Roman Emperor Otto III"

The Church of Saint Pantaleon (German: Sankt Pantaleon [ˌzaŋkt panˈtaːleɔn]; Kölsch: Zint Pantalejon [ˌtsɪ̂nt panˈtálɪjɔn]) is an early Romanesque church in Cologne, Germany. The church dates back to the 10th century and is one of the twelve Romanesque churches of Cologne. The former monastery church is consecrated to Saint Pantaleon and the Saints Cosmas and Damian and is the oldest church of the cult of Saint Pantaleon west of Byzantium. The Holy Roman Empress Theophanu and the archbishop Bruno the Great are buried in the church, which also contains shrines of saints Alban, the first Christian martyr of Britain, and Maurinus of Cologne. Pope Benedict XVI visited the church in 2005.

Otto III (June/July 980 – 23 January 1002) was the Holy Roman emperor and King of Italy from 996 until his death in 1002. A member of the Ottonian dynasty, Otto III was the only son of Emperor Otto II and his wife Theophanu.

Otto III was crowned as King of Germany in 983 at the age of three, shortly after his father's death in Southern Italy while campaigning against the Byzantine Empire and the Emirate of Sicily. Though the nominal ruler of Germany, Otto III's minor status ensured his various regents held power over the Empire. His cousin Duke Henry II of Bavaria, initially claimed regency over the young king and attempted to seize the throne for himself in 984. When his rebellion failed to gain the support of Germany's aristocracy, Henry II was forced to abandon his claims to the throne and to allow Otto III's mother Theophanu to serve as regent until her death in 991. Otto III was then still a child, so his grandmother, Adelaide of Italy, served as regent until 994.

The Holy Roman Empress or Empress of the Holy Roman Empire (Kaiserin des Heiligen Römischen Reiches) was the wife or widow of the Holy Roman Emperor. The elective dignity of Holy Roman emperor was restricted to males only, but some empresses, such as Theophanu and Maria Theresa, were de facto rulers of the Empire.

Otto II (955 – 7 December 983), called the Red (German: der Rote), was Holy Roman Emperor from 973 until his death in 983. A member of the Ottonian dynasty, Otto II was the youngest and sole surviving son of Otto the Great and Adelaide of Italy.

Otto II was made joint-ruler of Germany in 961, at an early age, and his father named him co-Emperor in 967 to secure his succession to the throne. His father also arranged for Otto II to marry the Byzantine Princess Theophanu, who would be his wife until his death. When his father died after a 37-year reign, the eighteen-year-old Otto II became absolute ruler of the Holy Roman Empire in a peaceful succession. Otto II spent his reign continuing his father's policy of strengthening Imperial rule in Germany and extending the borders of the Empire deeper into Southern Italy. Otto II also continued the work of Otto I in subordinating the Catholic Church to Imperial control.

Queen of Italy (regina Italiae in Latin and regina d'Italia in Italian) is a title adopted by many spouses of the rulers of the Italian peninsula after the fall of the Roman Empire. The details of where and how the ruling kings ruled are in the article about them. The elective dignity of Roman Emperor was restricted to males only; therefore, there was never an Italian Queen regnant, though women such as Adelaide of Italy and Theophanu and Maria Theresa of Austria, who controlled the power of ruling, ruled as de facto Queens Regnant.