Olav Magnusson, born in the year 1099, ascended to the throne of Norway in 1103 following the death of his father, King Magnus Barefoot. He shared the kingship with his half-brothers, Sigurd Jorsalfar and Øystein Magnusson, during a time when he was still quite young. This period marked the beginning of his reign, which lasted until 1115.
Despite being a king for twelve years, Olav's impact on the nation was minimal compared to that of his brothers. His youth meant that Sigurd and Øystein often took on the responsibilities of governance, with Øystein particularly noted for his efforts in stabilizing and strengthening the kingdom.
In 1107, Sigurd embarked on a Norwegian crusade to support the newly formed Kingdom of Jerusalem, returning in 1111. During this time, Olav remained under the regency of his brothers, who worked diligently to ensure the kingdom's prosperity.
Tragically, Olav's life was cut short when he fell ill and passed away at the tender age of sixteen in 1115. His reign concluded with his brothers succeeding him, and he was historically referred to as 'Olav IV' until the year 1957, when the numbering was adjusted with the ascension of Olav V.