The racehorse owner Lady Rothschild has died at the age of 83, her family has announced.
She died in hospital on Sunday having "fought a recent illness most valiantly", a spokeswoman said.
Lady Rothschild ran Waddesdon Stud in Buckinghamshire. In 2011, her colt, Nathaniel, won the King George VI and Queen Elizabeth Stakes at Ascot.
Born Serena Mary Dunn, she was the daughter of financier Sir James Dunn, and married Lord Rothschild in 1961.
She and her investment banker husband had four children and eight grandchildren.
Nathaniel clashed on more than one occasion with the legendary racehorse, Frankel, and ended his career with a third place behind the unbeaten colt in the 2012 Champion Stakes.
In 2006 Lady Rothschild paid a then record 4.6 million guineas for a broodmare when purchasing Magical Romance.