Complex sentence: The House of Bruce originated in Normandy in the 11th century, where the family took its name from Bruis (present-day Brix), where the earliest known member of the family, Adam de Brus, built a castle.
Split into simpler sentences: The House of Bruce originated in Normandy in the 11th century, where the family took its name from Bruis (present-day Brix). It was here that the earliest known member of the family, Adam de Brus, built a castle.