Horse racing. Up until recently, it was something I knew very little about. Today though? I can’t get enough of it. Even if you’ve never watched a horse race in your life, you’ve probably still heard of the Kentucky Derby and the Triple Crown. There are also probably a few horses out there you’ve heard of. Sea Biscuit is one, along with Secretariat. It helps that several movies have been made about them.

The Triple Crown (formally known as the “Triple Crown of Thoroughbred Racing”) is a title awarded for winning three specific horse races. Each of these races can only be done when a horse is three years old, so a horse only has one chance to become a Triple Crown. As for the three races, you’ve already heard of one of them, the Kentucky Derby. The other two are the Preakness Stakes and Belmont Stakes. Since 1875, only eleven horses have won the triple crown. That said, two other horses have effectively won it as well.

One of those two horses was the famous Man o’ War. If you haven’t heard of Man o’ War then you’ve certainly heard of his descendents. War Admiral was his son, and Sea Biscuit was his grandson (through a different son). Man o’ War was bred by August Belmont Jr.. The Belmont Stakes race was named after his father. Man o’ War was born while Belmont Jr. was serving overseas during World War I. Belmont Jr.’s wife named the horse in honor of her husband.

Of the 21 total races during his career, Man O’ War won 20 of them. His only loss was due to a botched start. Horse races originally didn’t use starting gates. When the race suddenly started, Man o’ War was in the middle of turning around. Even so, Man o’ War lost by only a half-length (several feet), and was blatantly the fastest horse on the track. In his third year, 1920, Man o’ War won both the Preakness Stakes and Belmont Stakes. He did not win the Kentucky Derby, because he wasn’t entered. His owner felt that early May was too soon to race such a young horse. Man o’ War is widely considered the greatest horse of the 20th Century.

Today, Man o’ War’s line is still going strong as his descendants are still racing today. The horse Tiznow, born in 1997, is a direct male descendent of Man o’ War and has sired many racehorses himself.

In 1978, the most recent Triple Crown was awarded to Affirmed, the great-great-grandson of War Admiral, and therefore also the great-great-great grandson of Man o’ War himself. Standing directly behind him though was his greatest rival, Aldyar.

Aldyar is the other horse besides Man o’ War who effectively won the Triple Crown. While Affirmed won all three races of the Triple Crown, Aldyar came in second in each of those exact same races. Had Affirmed not raced that year, Aldyar would have won the Triple Crown. He is the only horse in history to have this distinction. Not only that, all three races were close, with both horses racing side-by-side, and Affirmed barely holding onto his win each time. Breeders took notice though, and Aldyar’s offspring became as popular as any champion’s. Unfortunately Aldyar’s life ended in tragedy when he “broke” his leg and ultimately had to be euthanized. This is beyond tragic, because it is believed that Aldyar’s leg was broken intentionally by his owner J.T. Lundy, so he could collect the insurance. Lundy would go on to serve four years in prison for an unrelated fraud conviction. Aldyar is still remembered as a great horse, and Affirmed is especially well respected for winning the Triple Crown under such overwhelming competition.

If there is one horse that can hold a candle to the great Man o’ War then that is without doubt Secretariat. As the Triple Crown winner of 1973, Secretariat was the first champion to claim the title in 25 years. At the Kentucky Derby and Belmont Stakes, Secretariat set new record times that stand to this day almost 40 years later. Ultimately, Secretariat won 16 of his 21 races Of those five races he lost, he came in 2nd in three and 3rd in another.

Secretariat would retire after his third year and go on to sire roughly 600 foals. He soon came under criticism, however, for being incapable of siring stallions that could match his speed. In hindsight it is apparent that this is because Secretariat carried the “x-factor”. Now sure, normally a term like “x-factor” is a bunch of bunk, but in horse racing it means something very specific. Secretariat had heart. Literally. We’re not talking about attitude. When Secretariat passed away, it was discovered that his heart was over three times the size of a normal one, yet it was completely healthy. This trait is known as the “x-factor”, because it is believed to be passed along via the X chromosome. The trait has been traced back to a legendary horse named Eclipse who raced in England from 1769 to 1771. When Secretariat’s pedigree was further researched, it was discovered that his mother was a descendent of one of Eclipse’s daughters from 200 years before. Since the x-factor is attached to the X chromosome, stallions can only pass the trait on to their daughters.

As can be guessed then, while Secretariat’s sons were notably slow, his daughters became champions. And in turn, Secretariat’s grandsons through his daughters are also fast, most notably A.P. Indy. The legacy continues today with A.P. Indy’s daughter Rags to Riches, who was the first filly to win the Belmont Stakes in over a century when she did it in 2007.

While horseracing is a thrill to watch, it’s the horses themselves where the true stories are found. To watch the descendants of some of the greatest horses in the world take on the records of their ancestors is one of the best ways to come close to living history.