Complex sentence: He was a good dancer at the amateur theatre of the royal court, but was not very close to his mother; the Queen preferred her youngest children, Sophie Albertine and Frederick Adolf, but he and his oldest Gustav was described as close.
Split into simpler sentences: He was a good dancer at the amateur theatre of the royal court. Reportedly he was not very close to his mother; the Queen preferred her youngest children, Sophie Albertine and Frederick Adolf, but he and his oldest Gustav were described as close.