Where better could an Elector house his mistress and his illegitimate children than under his own nose? The Palais Bretzenheim - located directly opposite the palace - served as accommodation for Elector Karl-Theodors mistress Josepha Seyffert. In 1777, the children they had together received musical instruction here from no less a person than Wolfgang Amadeus Mozart. Fittingly, what was in the 18th century the city's largest and most noble residence today houses the Mannheim Family Court, among other offices.