Ordinance of Alsnö
The Ordinance of Alsnö or Statute of Alsnö () was an act by king Magnus Ladulås of Sweden, issued at Alsnö hus in 1279, giving exemption from land taxation to those nobles who committed to produce a heavy cavalryman to the king's service:  

This established the frälse, the tax-exempt secular nobility in Sweden. Another, perhaps less pivotal but more widely known, article of this act reformed the peasants' obligation to accommodate traveling nobles, a privilege that was at the time abused to the point of gatecrashing. As Magnus was acclaimed for "protecting the persons and goods of the common people and thus was nicknamed Magnus Ladulås (Magnus Barn-lock)"

See also
 History of Sweden
 Adelsö

References

1280s in law
Law of Sweden
1280 in Europe
13th century in Sweden