Complex sentence: Károly became an orphan at barely the age of one when both his parents were murdered by armed Romanian rebells in the summer of 1849, during their journey back home, but survived himself because he had been left behind with his grandmother at Alsósztregova castle.
Split into simpler sentences: Károly became an orphan at barely the age of one when both his parents were murdered by armed Romanian rebells in the summer of 1849, during their journey back home. At the time of the tragedy he had been left behind with his grandmother at Alsósztregova castle.