The Duff-Gordon family was a Scottish aristocratic family and the Baronet of Haklkin title eminates from a licence conferred on his great grand-uncle in 1813 during the Peninsular War. In 1772 his family founded the Duff-Gordon sherry bodega in Spain. The interests in the succesful company were bought out by the partner family and the company is still a succesful producer today, under that family name, Osborne. 

He married his wife, a famous fashion designer, in 1900. This was quite a risqué decision. Lucy Christiana Sutherland (then Mrs. James Stuart Wallace) was a divorcee and her sister, Elinor Glyn, was known as a writer of erotic fiction.

A proficient fencer who won a silver medal in the 1906 Olympics and organised the British fencing team at the 1908 Olympics. He boarded Titanic at Cherbourg with his wife, Lady Duff-Gordon and for some reason the couple signed onto the ship as Mr. and Mrs. Morgan.

On the night of the disaster he asked First Officer Murdoch if he and his wife could board lifeboat 1. The request was granted and the boat was launched with only 12 on board. 

Duff-Gordon was to become the centre of a scandal regarding accusations of bribery to crew onboard the lifeboat. He wrote in a private letter "There seems to be a feeling of resentment against any English man being saved....The whole pleasure of having been saved is quite spoilt by the venomous attacks they made at first in the papers. This, I suppose, was because I refused to see any reporter."

Despite the official vindication by the Board of Trade inquiry, public suspicion that the Duff-Gordons had acted selfishly tainted the couple for the remainder of their lives. The couple were estranged in 1915 although they never divorced and remained friends.

Sir Cosmo would spend much of the rest of his life a recluse and died in 1931 of natural causes.