Countess Anastasia Mikhailovna of Torby, CBE (9 September 1892 – 7 December 1977), otherwise styled Lady Zia Wernher, was the elder daughter ofGrand Duke Michael Mikhailovich of Russia, a grandson of Tsar Nicholas I of Russia, by Countess Sophie of Merenberg.

Like her mother, Anastasia was born of amorganatic marriage, and was ineligible to bear her father's title or rank. Following her parents'elopement to San Remo in 1891 and consequent banishment from Russia, Sophia was made Countess de Torby by Adolphe, Grand Duke of Luxembourg, which title extended to all three of the couple's children. Through her mother, she descended from the renowned Russian poet Alexander Pushkin, as well as from his ancestor Abram Petrovich Gannibal, Peter the Great's African protégé.

On 20 July 1917 Countess Anastasia de Torby married British Major-General Sir Harold Wernher, 3rd Bt (1893–1973) (son of wealthy financier, Sir Julius Wernher, Bt, who had made his fortune in South African diamonds). In the following September, she was accorded the style and precedence of the daughter of an earl by Royal Warrant of George V, and discontinued use of her comital title.[1] Henceforth she was known as Lady Zia Wernher.

The couple had one son and two daughters. Their firstborn, Captain George Michael Alexander Wernher, was born in 1918 and was killed in action in Egypt at the age of twenty-four. He never married and had no issue. Their elder daughter, Georgina Wernher, was born a year later and married and had issue with Lt. Col. Sir Harold Phillips.

The younger daughter, Myra Alice, was born in 1925 and married and had issue with Major Sir David Henry Butter.

Through her daughters, Zia's grandchildren at the beginning of the 21st century included sisters who were the Duchesses, respectively, of Abercorn and Westminster, and another pair of sisters, the Countess of Dalhousie (née Maralyn Butter), and Princess Alexander Galitzine (née Rohays Butter).

1. George Michael Alexander
2. Georgina Kennard. Married Lt.-Col. Harold Phillips (1909–1980)
   1. Alexandra Hamilton, Duchess of Abercorn (born 27 February 1946)
   2. Nicholas Harold Phillips (23 August 1947 – 1 March 1991)
   3. Fiona Mercedes Phillips (born 30 March 1951)
   4. Marita Georgina Phillips (born 28 May 1954)
   5. Natalia Grosvenor, Duchess of Westminster (born 8 May 1959)
3. Myra Alice Wernher. Married Major Sir David Henry Butter
   1. Maralyn Ramsay, Countess of Dalhousie (née Maralyn Butter)

Zia's younger sister was Countess Nadejda de Torby, wife of George Mountbatten, 2nd Marquess of Milford Haven, a descendant of Queen Victoria and maternal uncle to The Duke of Edinburgh.