Complex sentence: In the early 12th century a house of free nobles appeared in Breisgauer records, who called themselves "Herren von Horwen" (lords of horwen) and had close ties to the Abbey of St. Gallen.
Split into simpler sentences: In the early 12th century, a house of free nobles occurred in Breisgauer records. They called themselves "Herren von Horwen" (lords of horwen) and had close ties to the Abbey of St. Gallen.