Complex sentence: Queen Christina of Sweden raised her illegitimate half-brother to comital dignity and gave him The Countship of Nystad in 1647, when the family was registered to the Swedish House of Knights as its sixth comital family.
Split into simpler sentences: Queen Christina of Sweden raised her illegitimate half-brother to the dignity of a count when she gave him the Countship of Nystad in 1647. He and his family were registered to the Swedish House of Knights as its sixth comital family.