Following the death of the 10th Duke's eldest son, William Cavendish, who was killed in action during the Second World War, the title passed to his second son, Andrew.
Like his brother, Andrew also served in the Coldstream Guards during the Second World War and was awarded the Military Cross in recognition of gallant and distinguished services.
After the war, he was Mayor of Buxton from 1952 - 1954 and later served as a minister in the Conservative government from 1960 - 1964.
In 1941, the 11th Duke married the Hon. Deborah Mitford, daughter of Lord Redesdale. Together they had three children, Emma (b. 1943), Peregrine (b. 1944), and Sophia (b. 1957).
The Duke and his family lived at Edensor House in the park at Chatsworth from 1947. In 1957 the decision was taken to move back to Chatsworth. Some internal modernisation was required, including a new central heating system and the adaptation of rooms for modern living. In November 1959 the work was completed and the family moved in.
Following the 10th Duke's unexpected death in 1950, the maximum rate of death duties at 80% had to be paid. Some of the most important works of art and many rare books, as well as Hardwick Hall and its estate, were given to the Treasury in lieu of cash. Thousands of acres of land and other assets were sold. The ownership of all remaining Derbyshire estates then passed to the Trustees of the Chatsworth Settlement.
In 1981 the running of Chatsworth was taken over by the Chatsworth House Trust, a charity established by the 11th Duke to help ensure the preservation of the house, its contents, the garden, and the park for the benefit of the general public.
The Duke retained the title for 50 years and remains the longest-serving head of the family. During his time, he and Duchess Deborah worked to establish Chatsworth as a popular visitor attraction, adding retail shops, cafes and restaurants, a farmyard and playground, and the estate farm shop.
On his death in 2004, he was succeeded by his son, Peregrine.