Complex sentence: Owing to the early death of his Danish mother, the child was left much to his own devices and developed a fondness for semi-poetical performances, organising his companions in heroic games, in which he himself took such parts as those of Peder Tordenskjold and Niels Juul.
Split into simpler sentences: Owing to the early death of his mother, who was a Dane, the child was left much to his own devices. He soon developed a fondness for semi-poetical performances, and loved to organize among his companions heroic games, in which he himself took such parts as those of Tordenskjold and Niels Juul.