text: At the request of his mother, this king built a castle for unmarried daughters of the nobility at Quedlinburg.
full_question: At the request of his mother, this king built a castle for unmarried daughters of the nobility at Quedlinburg. Archbishop William of Mainz oversaw the compilation of a liturgical book commissioned by this king, the Romano-German Pontifical. This man was assisted in one battle by a son-in-law whose death was related in a chronicle by Widukind of Corvey. After Conrad the Red helped him to defeat the chieftains Bulcsu, Lel and Sur, this king married his son to the Byzantine princess Theopanu. This son of Henry the Fowler defeated the Magyars at the Battle of Lechfeld. For 10 points, name this German crowned by Pope John XII as the first Holy Roman Emperor.
first_sentence: At the request of his mother, this king built a castle for unmarried daughters of the nobility at Quedlinburg.
raw_answer: Otto the Great [or Otto I; prompt on Otto]