Dagmar Rosita Astrid Libertas, Duchess of Marlborough (née Douglas, sometimes Spencer-Churchill; born 26 September 1943), is a British artist of Swedish and German descent.
She was born as Countess Rosita Douglas in Madrid, Spain, the younger daughter of Count Carl Douglas (1908–1961), a Swedish nobleman and diplomat who was Ambassador to Brazil, and his Prussian wife Ottora Maria Haas-Heye (1910–2001), maternal granddaughter of Prince Philip, 1st Prince of Eulenburg and Hertefeld, by his wife Augusta, Countess Sandels.
She grew up as a diplomat's child, travelling all over the world but spent her summers at the family home, the castle of Stjärnorp, which belonged to Rosita's paternal grandfather, General Archibald Douglas.
[1] On 20 May 1972, Rosita Douglas became the third wife of John Spencer-Churchill, 11th Duke of Marlborough, an Englishman who had inherited his father's estates and titles two months earlier.
However, her father's patriline is Scottish, of the Swedish-German branch, descended via two obscure generations[6] from the youngest son of James Douglas, 1st Baron of Dalkeith, ancestor of the 15th century Earls of Morton.