Rubuta ci gaba don wannan sakin layi - A lokacin ƙuruciyarsa, ya girma a kotun Sweden tare da dan uwansa Sarauniya Christina, ya sami kyakkyawan ilimin farar hula. Daga baya Charles X ya koyi fasahar yaƙi a ƙarƙashin Lennart Torstenson, yana nan a karo na biyu na Breitenfeld (1642) da kuma a Jankowitz
(1645). (a cikin harshen Hausa) Daga 1646 zuwa 1648 ya halarci kotun Sweden, wanda ake zaton shi ne mijin da zai iya zama dan uwansa sarauniya mai mulki, Christina na Sweden (1626-89, ya yi sarauta 1632-54), amma rashin amincewarta da yin aure ya kawo ƙarshen waɗannan tsammanin, kuma don biyan dan uwanta don karya alkawarin rabin alkawari ta bayyana shi a matsayin magajinta a 1649, duk da adawa da Privy Council wanda Axel Oxenstierna ya jagoranci. A shekara ta 1648 ya sami mukamin kwamandan sojojin Sweden a Jamus. Kammalawa na yarjejeniyar Westphalia a watan Oktoba 1648 ya hana shi cin nasarar laurels na soja da aka ce yana so, amma a matsayin wakili na Sweden a majalisa na Nuremberg, yana da damar da za ta koyi diplomasiyya, kimiyya da aka kwatanta da shi da sauri. A matsayinsa na magajin gadon sarauta, matsayinsa a kan dawowarsa Sweden yana da haɗari saboda rashin jin daɗin sarauniyar. Saboda haka ya koma tsibirin Öland har sai da Christina ya yi watsi da shi a ranar 5 ga Yuni 1654 ya kira shi zuwa kursiyin.