sentences:  The conclusion of the treaties of Westphalia in October 1648 prevented him from winning the military laurels he is said to have desired, but as the Swedish plenipotentiary at the executive congress of Nuremberg, he had an opportunity to learn diplomacy, a science he is described as having quickly mastered.As the recognized heir to the throne, his position on his return to Sweden was dangerous because of the growing discontent with the queen.He therefore withdrew to the isle of Öland until the abdication of Christina on 5 June 1654 called him to the throne.