Olaf IV of Norway was a king who ruled from 1387 until his death in 1387. He was born in 1370 and was the son of Haakon VI of Norway and Margaret I of Denmark. Olaf became king at a young age after his father passed away, but his reign was short-lived due to his untimely death at just 17 years old. During his reign, Olaf IV was also the king of Sweden and Denmark, as he was part of the Kalmar Union, which sought to unite the three kingdoms under a single monarch. His death led to a power struggle, and the union continued to face challenges in the years that followed.