Recommended reading - HORSES OF WAR - a true story

December 1919, Russian Revolution, Joseph Clements a former English jockey is determined to save two precious Epsom Derby winners, Min and Boy, stallions in the Imperial Stud Kharkov. Paralleled to the story is his dedicated love for Princess Katya Mironov whom he marries in a chapel with no witnesses nor Priest when the Bolsheviks bore down on Kharkov.

Min, is Minoru, who won the 1909 Guineas and Derby and who is the 6th generation of Northern Dancer.
Boy, is Aboyeur, who won the disputed Derby of 1913 in which the King's Horse was brought down by a suffragette.

A fanatastic read for all but a caveat that it does not have a "happy" ending.

Horses Of War by Duff Hart-Davis, ISBN 1-85619-062-5