Lews Castle was built in the years 1847-1857 as a country house for Sir James Matheson who had bought the whole island a few years previously with his fortune from the Chinese Opium trade. It was designed by the Glasgow architect Charles Wilson.
In 1918, the Lewis estate including the castle was bought by industrialist Lord Leverhulme from the Matheson family. He gave the castle to the people of Stornoway parish in 1923.
During World War II the Castle was taken over as accommodation for air and ground crew of 700 Naval Air Squadron, who operated a detachment of six Supermarine Walrus aircraft from a slipway at Cuddy Point in the Grounds. The base was referred to as HMS Mentor.
After the war, the Castle was also used for accommodation for students of Lews Castle College in the 1950s.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.