sentences:  By 1819 the castle was in ruins.King William I of Württemberg (whose father, Frederick III, Duke of Württemberg became king in 1806) built Württemberg Mausoleum on the hill for his second wife Queen Catherine (1788–1819) (daughter of Tsar Paul I of Russia and Sophie Dorothea of Württemberg ).After his death in 1864, King William was also buried in the mausoleum (German