Otto II (955 December 7, 983), called the Red, was the third ruler of the Saxon or Ottonian dynasty, the son of Otto the Great and Adelaide of Italy. Born in the year 955, Otto received his education under the care of his uncle, Bruno, archbishop of Cologne, and his illegitimate half-brother, William, archbishop of Mainz. Needing to put his affairs in order prior to his descent into Italy, his father had Otto elected German king at Worms in 961, and crowned at Aachen Cathedral on May 26, 961. Later, he was crowned joint Emperor at Rome by Pope John XIII on December 25, 967. Although the nominal co-ruler, he exercised no real authority until the death of his father.