Christian I was a king of Denmark and Norway, reigning from 1448 to 1481. He was born in 1426 and became the first monarch of the House of Oldenburg. His rule marked the beginning of the Kalmar Union, which united the three kingdoms of Denmark, Norway, and Sweden under a single monarch. During his reign, Christian I focused on strengthening the central authority of the monarchy and promoting trade. He also established the University of Copenhagen in 1479, which became an important center of learning in Scandinavia. His legacy includes efforts to consolidate power and foster cultural development in the region.