As Thoroughbred racing navigates through the twenty-first century, it can be said without question that the Santa Anita Derby ranks among the most prestigious Kentucky Derby prep races in the land.

Many horses that have started in the race have gone on to become a Kentucky Derby champion, with local legends like Swaps, Majestic Prince, Affirmed and California Chrome among the members of that exclusive club.

You might be able to name several Kentucky Derby winners that came out of the Santa Anita Derby, but do you know who the first horse was to do so?

You have to go back a long time to find the answer. That horse was named Gallahadion, and he competed long before any of those aforementioned equines.

Entering the 1940 Santa Anita Derby, Gallahadion was already a stakes winner at the meet, having taken the San Vicente. Part of a coupled entry favored to win the Santa Anita Derby, it was not Gallahadion's day as he finished way back in thirteenth place. But that setback did not prevent a trip to Churchill Downs on the first Saturday in May.

The 66th Kentucky Derby featured a medium-sized group of horses, far from the nineteen or twenty that is commonplace nowadays. Of the eight Thoroughbreds who started the contest, the majority expected reigning Two-Year-Old champion Bimelech to reach the wire first. And Gallahadion? He was among the biggest longshots in the field.

The Kentucky Derby actually served as a rematch for them. Squaring off in the Derby Trial a couple of days earlier, Bimelech finished his prep season with a win while Gallahadion followed him home in second. Though the Derby result had yet to be determined, they would be close to each other for at least a few moments. Gallahadion drew the rail, and Bimelech was next door in post two. But would they be one-two again?

They both started well, getting into early contention as Roman set the pace early on. That stayed the case as the field entered the backstretch. But Bimelech soon took over as those who bet on him likely readied themselves for the predicted result.

But Gallahadion had different ideas.

Racing in the stretch, the son of Sir Galahad III moved along the rail. An untold number of fans to his left in the infield watched as he took the lead from Bimelech, who ran on the longshot's outside. Bimelech may have been the favorite, but he had no answer for the Roy Waldron trainee that day.

To the shock of countless people, Gallahadion and jockey Carroll Bierman won the Kentucky Derby in a huge upset at 35-1 for Milky Way Farm. Not only did he thwart Bimelech, Gallahadion also defeated fellow Southern California horse Mioland, a member of Charles Howard's stable who beat him in the Santa Anita Derby.

As it turned out, there was some Kentucky Derby history in Gallahadion's pedigree. His grandfather, Reigh Count, was champion of the 1928 edition. On top of being a surprise winner, Gallahadion added another Derby to his family's collection.

But Gallahadion did more than just win the Derby. No one at Churchill Downs or Santa Anita knew it, and it would not be known for many years, but Gallahadion began a line of prestige under the Twin Spires in 1940. He stood as the first horse in six iterations of the Santa Anita Derby to triumph in the Run for the Roses, setting a path that has since been followed by horses like Hill Gail, Swaps, Majestic Prince, Affirmed, Ferdinand, Sunday Silence, and many others. He played a pivotal role in shaping the Santa Anita Derby into the major prep race it is now.

It is probably not a stretch to say that most fans who visit Santa Anita in the present day do not know of Gallahadion. But he is a significant figure in the timeline of California racing.

In fact, given his history with the Santa Anita and Kentucky Derbies, one could say he is a trailblazer.