Magnus I of SwedenMagnus I of Sweden
), by name Magnus Barnlock
: Magnus Ladulås
) was king
until his death in 1290
. Historians debate whether his epithet is because of his decree of 1279 overthrowing the law that required peasants to provide sustenance for the nobles when they moved from estate to estate ("Peasants! Lock your barns!) or because his second name might have been Ladislaus.
With the declaration of the Alsnö stadga 1279, Magnus Ladulås gave the knights, (or anyone who supported the crown with a warrior on a horse) freedom from tax (a freedom called Frälse in Swedish) this was the formal foundation of the Swedish nobility.
Son to Birger Jarl (earl Birger Magnusson) and princess Ingeborg Eriksdotter of Sweden. Magnus Ladulås married 1276 Helvig of Holstein, a daughter of Gerhard I of Holstein.
- Ingeborg Magnusdotter of Sweden, born abt. 1279 cirka. Married Erik Menved of Denmark.
- Birger Magnusson of Sweden, born abt. 1280 king of Sweden.
- Eric Magnusson of Sweden, duke, born abt. 1282. Died out of starvation 1318 in prisoned by his brother Birger, at Nyköpingshus castle.
- Valdemar Magnusson, duke, Died out of starvation 1318 in prisoned by his brother Birger, at Nyköpingshus castle.
- Rikissa Magnusdotter. (an abbess) Died after 1347.