His racing career was ended by injury soon afterwards, and he was retired to stud, where he became an extremely successful and influential breeding stallion, both in Europe and North America.

Blenheim's dam, Malva (1919–1941) who stood barely 15 hands, won three minor races for Lord Carnarvon before becoming a highly successful broodmare.

Ridden by Dawson's stable jockey Michael Beary he started at odds of 7/2 and won from Lord Woolavington's Press Gang.

On his final race of the season he started favourite for the Middle Park Stakes but finished second by half a length to Press Gang.

[3] Blenheim was slow to find his form as a three-year-old and began his 1930 campaign by running unplaced behind Christopher Robin in the Greenham Stakes at Newbury.

[4] The race attracted its customary huge crowd, with the spectators including the King and Queen as well as the Prince of Wales and the Duke of York.

Blenheim was produced by Wragg with a perfectly timed run to take the lead inside the final furlong and won by a length from Iliad with Diolite in third.

In his first crop of foals, he sired Mumtaz Begum (bred eight winners, including Nasrullah), followed the next year by Mahmoud, who won the 1936 Epsom Derby.