Rotenberg is a village which is a part of the Untertürkheim district of the City of Stuttgart, Germany. The area overlooks Untertürkheim and the Neckar valley and lies on the north and east slopes of the hill known as Württemberg. On this hill the first castle of the Counts of Württemberg was built in 1083 by Conrad of Beutelsbach who subsequently became Konrad I, Count of Württemberg and is considered the founder of the Württemberg dynasty.
The hill also gave its name to the State of Württemberg. The castle was rebuilt in 1316 by Count Eberhard I. However, in about 1330 Eberhard built the "Old Castle" in what is now the centre of Stuttgart. The castle on Württemberg fell into disuse as a royal residence.
In 1534 the castle was rebuilt a third time by Ulrich, Duke of Württemberg who had been restored to the throne after entering exile in 1519.
By 1819 the castle was in ruins. King William I of Württemberg built Württemberg Mausoleum on the hill for his second wife Queen Catherine. After his death in 1864, King William was also buried in the mausoleum. Today the mausoleum is an important local landmark as it is visible from many areas of east Stuttgart.