▁died ▁in ▁the ▁battle . ▁ ▁A ▁medieval ▁Liber ▁D atic us ▁( Book ▁of ▁Don ations ) ▁from ▁Lund ▁states ▁that ▁an ▁arist ocrat ▁called ▁Magn us ▁fell ▁at ▁the ▁Battle ▁of ▁L ena ▁(" II ▁Kal . ▁Februar . ▁ob i it ▁Magn us , ▁qui ▁occ is us ▁est ▁in ▁G ocia ▁ap ud ▁L ene , ▁An no ▁Domin ice ▁inc arn ation is ▁M CC V III "). ▁The ▁equation ▁of ▁this ▁Magn us ▁with ▁Magn us ▁Minn is ki öld ▁is ▁not ▁certain , ▁however . ▁The ▁remains ▁of ▁his ▁son ▁Bir ger ▁Jar l ▁have ▁been ▁exam ined , ▁and ▁they ▁indicate ▁that ▁he ▁was ▁ 5 0 – 5 5 ▁years ▁old ▁when ▁he ▁died , ▁and ▁Magn us ▁was ▁therefore ▁probably ▁still ▁alive ▁some ▁years ▁after ▁the ▁L ena ▁battle . ▁ ▁References ▁ ▁Further ▁reading ▁Harrison , ▁Dick ▁( 2 0 0 2 ) ▁Jar l ens ▁se kel : ▁en ▁ber ätt else ▁om ▁ 1 2 0 0 - t ale ts ▁Sverige . ▁Stockholm : ▁Ord front . ▁Ko ht , ▁Half dan ▁ ▁( 1 9 2 9 ) ▁The ▁Sc and in av ian ▁Kingdom s ▁until ▁the ▁end ▁of ▁the ▁th ir teenth ▁century '' ▁ ▁( C amb ridge ▁University ▁Press ) ▁ ▁Category : S wed ish ▁nob ility ▁Category : S wed ish ▁polit icians ▁Category : Year ▁of ▁birth ▁uncertain ▁Category : Year ▁of ▁death ▁uncertain ▁Category : 1 3 th - century