While looking through wikipedia I came upon this list. All other recipients are German so why did he receive it? Was this because he fought alongside the Prussians during the sixth coalition? Do we know how he reacted to being awarded it? How did the other recipients feel to him being awarded it?
He led the Army of Northern Germany (including the Swedish army, a Prussian and a Russian Corps) of about 120 000 men during the Coalition's German campaign in 1813 and won victories at Großbeeren and Dennewitz and partook in the Battle of Leipzig.
As a victorious General allied to the Prussians, he was awarded the Grand Cross of the Iron cross for his participation in the campaign, despite being slow and very careful about risking Swedish lives in the battles he fought, as he considered the need for his troops against the Danes and Norwegians in the upcoming campaign to force Norway into a personal union with Sweden.
Source: Jean-Baptiste Bernadotte by Margareta Beckman.