Valdemar Birgersson was the son of princess Ingeborg Eriksdotter of Sweden and Birger Jarl, Earl Birger Magnusson of Sweden, who more or less ruled Sweden under the official king Eric Ericsson the lame. When king Eric Ericsson died 1250, Valdemar was elected king in his father's absence. Birger Jarl was on crusade in Finland.

Valdemar never really ruled Sweden since his father Birger held an iron grip over the country. After the death of Birger he soon came into conflict with his brother who wanted the throne.

Meanwhile, Valdemar had a relationship with his wifes sister (both of them princesses of Denmark) and had to go to Rome in order to get the Popes forgiveness. After his return, he was later imprisoned by his brother Magnus, (later Magnus I of Sweden) who was elected king.

Preceded by:
Eric XI of Sweden
List of Swedish monarchs Succeeded by:
Magnus I of Sweden