Charles Henry Gordon-Lennox, the tenth Duke of Richmond, had attracted national interest in the 1960s when he and the Duchess, Susan Grenville-Grey, adopted two children of mixed-African heritage, an unusual step at the time.
His son, and heir to the title, the Earl of March and Kinrara, Charles Henry Gordon-Lennox, said: “He was a very progressive thinker, particularly for someone in his position - he was not typical.
“They felt that interracial adoption would be a good thing, they did a lot of things that they believed in.”
Lord March, who will inherit his late father’s title, becoming the 11th Duke of Richmond, said his father did not constrain his life to the traditional sort some might expect of his position.
The two British-born girls the couple adopted had South African and Ghanaian heritage, respectively. One is actress Nimmy March, whose birth father was South African.
The couple were also interested in sustainable farming practices, his mother kept grain-fed livestock before it was popular and his father ate organic apples, Lord March said.
He also began the process of secession earlier than was traditionally required, moving out of Goodwood House and moving his son and his family in when he turned 40: “He was always very positive about anything I wanted to do.”
The late Duke of Richmond was educated at Eton and rose to the rank of lieutenant in the King’s Royal Rifle Corps. He later became an accountant, then succeeded to the dukedom in 1989.
He was a chairman and patron of a string of boards and societies, and had a long-standing association with both the Church of England and the University of Sussex, where he served as chancellor.
He is survived by five children, 13 grandchildren, and one great-grandchild.