Christopher I of Denmark was a king who ruled from 1440 to 1448. He was born in 1426 and was a member of the House of Oldenburg. Christopher became king after the death of his father, Eric of Pomerania, and was known for his efforts to strengthen the union of the Kalmar Union, which united Denmark, Norway, and Sweden under a single monarch. During his reign, Christopher faced challenges, including conflicts with the nobility and issues related to governance. His rule was relatively short, and he died in 1448, leading to a succession crisis that affected the stability of the Kalmar Union.