(953-991)
Charles was born in Laon, France, the younger son of Louis IV d'Outremer and Queen Gerberge. Following a palace intrigue, he was exiled by his brother Lothair, now king. Switching sides to Lothair's rival, Holy Roman Emperor Otto II, Charles secured the title of duke of Lower Lotharingia from the latter. He took the oath of vassalage about June 977. Charles built his castrum on the Senne River in 977-979. He built here because he owned lands at the site, but historians dispute how he acquired his property. Tradition holds he did so through his mother, the daughter of Emperor Henry I and sister of Emperor Otto I. From 977, consequent to Charles's residency, one can speak of the county of Brussels.
Historical Dictionary of Brussels. Paul F. State.