Otto II (955 – December 7, 983), called the Red (Rufus), is Holy Roman Emperor from 973 to his death in 983.

A member of the Ottonian dynasty, Otto II is the youngest and sole surviving son of Otto the Great and Adelaide of Italy.

From an early age, Otto II is made joint-ruler of Germany in 961 and then Co-Emperor in 967 alongside his father Otto I in order to secure Otto II's succession to the throne.

His father arranges for Otto II to marry the Byzantine Princesses Theophanu, who will be his wife until his death.

When his father dies after a 37-year reign, the eighteen-year old Otto II becomes absolute ruler of the Holy Roman Empire in a peaceful succession.

Otto II spends his reign continuing his father's policy of strengthening Imperial rule in Germany and extending the Empire's borders deeper into southern Italy.

Otto II also continues the work of Otto I in subordinating the Catholic Church to Imperial control.

Early in his reign, Otto II experiences a major revolt against his rule from other members of the Ottonian dynasty who claim the throne for themselves.

Otto II's victory allows him to exclude the Bavarian line of Ottonians from the line of Imperial succession.

This strengthens Otto II's authority as Emperor and secures his own son's succession to the Imperial throne.

With domestic affairs settled, from 980 onward, Otto II focuses his attention to annexing the whole of Italy into the Empire.

His conquests bring him into conflict with the Byzantine Empire and with the Muslims of the Fatimid Caliphate, both holding territories in southern Italy.

After initial successes in unifying the southern Lombard principalities under his authority and in conquering Byzantine-controlled territory, Otto II's campaigns in southern Italy end in 982 following a disastrous defeat by the Muslims.

While in the process of preparing to counterattack the Muslim forces, in 983 Otto II experiences a major uprising of the Slavs against his rule, forcing the Empire to abandon its major territorial holdings east of the Elbe river.

Otto II dies suddenly in 983 at the age of 28 after a ten-year reign.

Succeeded by his three-year old son Otto III as Emperor, Otto II's sudden death places a minor on the Imperial throne and plunges the Empire into political crisis.