A ducal castle, "dat Nyehus" (the new house) was first mentioned in 1369. The name of the castle became eponymous for Neuhaus upon Elbe, a component of today's Amt Neuhaus. It served the duchess dowager Catherine (*1488 – 29 July 1563*, Neuhaus), widow of Magnus I, as residence until her death. Around 1600 Duke Francis II restored Neuhaus Castle. In 1616 the ducal residential castle in Lauenburg upon Elbe, started in 1180–1182 by Duke Bernard I, burnt down and Duke Francis II then used Neuhaus Castle as his residence. On 23 May 1624 Francis' daughter Sophia Hedwig (Lauenburg upon Elbe, *24 May 1601 - 21 February 1660*, Glücksburg) married Philip, Duke of Schleswig-Holstein-Sonderburg-Glücksburg in Neuhaus Castle.