from Wikipedia, re Prince Michael of Kent,
Tsar Nicholas II was a first cousin of three of his grandparents: George V, Prince Nicholas of Greece and Denmark, and Grand Duchess Elena Vladimirovna of Russia. When the bodies of the Tsar and some of his family were recovered in 1991, the remains were later identified by DNA using, among others, a sample from Prince Michael for recognition.[32] He attended the 1998 burial of the Tsar and his family in St Petersburg