King Olaf II of Norway, also known as Olaf Haraldsson, reigned from 1015 to 1028. He is best known for his efforts to convert Norway to Christianity and for unifying the country under a single rule. His reign was marked by battles against local chieftains and the establishment of a more centralized government. After his defeat at the Battle of Stiklestad in 1030, Olaf II was killed, and he became a martyr in the eyes of many Norwegians. He was later canonized as Saint Olaf, and his legacy continues to influence Norwegian culture and identity today.