▁and ▁the ▁castle ▁remain ▁open ▁for ▁various ▁interpret ations , ▁as ▁do ▁the ▁size ▁and ▁extent ▁of ▁the ▁city ▁at ▁the ▁time . ▁ ▁Some ▁research ers ▁conclude ▁Stockholm ▁evol ved ▁into ▁the ▁Swedish ▁capital ▁and ▁an ▁important ▁trade ▁city ▁before ▁ 1 2 0 0 ▁( K um li en ), ▁while ▁others ▁suggest ▁the ▁location ▁remained ▁a ▁mostly ▁rural ▁area ▁around ▁ 1 2 5 0 ▁to ▁quickly ▁expand ▁into ▁the ▁large ▁city ▁before ▁the ▁castle ▁was ▁completed ▁( H ans son , ▁Ö d man ). ▁ ▁Origin ▁of ▁the ▁name ▁ ▁The ▁first , ▁verified , ▁mention ▁of ▁the ▁name ▁' Sto ck holm ' ▁is ▁from ▁two ▁letters ▁written ▁in ▁Latin ▁in ▁ 1 2 5 2 ; ▁the ▁first , ▁written ▁in ▁July , ▁is ▁a ▁letter ▁where ▁the ▁King ▁Val dem ar ▁and ▁Bir ger ▁Jar l ▁offered ▁their ▁royal ▁patron age ▁to ▁F og d ö ▁Ab bey ; ▁and ▁the ▁other , ▁written ▁by ▁Bir ger ▁Jar l ▁in ▁August , ▁ur ged ▁the ▁pe asant ry ▁in ▁Att und aland ▁to ▁pay ▁their ▁t ith es ▁to ▁the ▁U pp s ala ▁C athedral . ▁ ▁Both ▁letters ▁were ▁written ▁in ▁Stockholm , ▁but ▁give ▁no ▁further ▁information ▁of ▁the ▁city ▁itself ▁or ▁any ▁explanation ▁on ▁the ▁background ▁of ▁the ▁name . ▁ ▁However , ▁it ▁can ▁be ▁assumed ▁at ▁least ▁some ▁sort ▁of ▁dwell ing ▁in ▁consist ence ▁with ▁the ▁station ▁of ▁a ▁Swedish ▁jar l ▁existed ▁at ▁that ▁time . ▁