The 10th Group 1 stakes win by So You Think in Wednesday’s Prince of Wales’s Stakes at Royal Ascot was part of a family day for trainer Aidan O’Brien.

His son Joseph won his first career race at Royal Ascot aboard So You Think, who won by 2 1/4 lengths as the 4-5 favorite, defeating Carlton House, owned by the Queen of England.

Earlier on the six-race program, Aidan O’Brien won the Group 3 Jersey Stakes with the 20-1 shot Ishvana, owned by his wife, Ann Marie.

The Group 1 Gold Cup, a 2 1/2-mile race, headlines Thursday’s action at Royal Ascot, with Fame and Glory widely expected to win for the second year in a row.

Fame and Glory, a 14-time winner trained by Aidan O’Brien, won the 2011 Gold Cup by three lengths over return rival Opinion Poll and had a useful prep race winning a listed stakes May 20 at Navan.

The Group 2 Ribblesdale Stakes matches Shirocco Star, The Fugue, and Twirl, respectively the two-three-four finishers from the Group 1 Epsom Oaks.

Imagine the New York Yankees playing a semi-pro team from rural Wisconsin, and you will get an idea what Frankel is doing to the other milers who have dared face him in England.

So You Think, the 6-year-old New Zealand-bred horse, has won nine Group 1 races in his career in locations as diverse as Australia, England, and Ireland.

Later this year, So You Think will begin stud duty in Australia. Until then, he has time to add to his record. On Wednesday, he will be a heavy favorite to win the Group 1 Prince of Wales’s Stakes over 1 1/4 miles on turf at Royal Ascot.

Trained by Aidan O’Brien, So You Think has padded his record this year, with a six-length win in the Group 1 Tattersalls Gold Cup at The Curragh in May.

Frankel on one end, Black Caviar on the other: As far as bookends go, the Royal Ascot meeting has done pretty well by itself.

The undefeated 3-year-old filly Beauty Parlor is quietly being mentioned in the same breath as the great Irish-bred, French-raced filly Zarkava, who was retired in 2008 unbeaten in seven starts.

From start to finish, the five-day Royal Ascot meeting that begins Tuesday is loaded with superstars.

The highlight of the first day is the appearance of the undefeated champion Frankel in the Group 1 Queen Anne Stakes over a mile. Perfect after 10 starts, including the Group 1 Lockinge Stakes at Newbury, England, on May 19, Frankel was a 1-8 shot with bookmakers to win the Queen Anne Stakes as of Friday.

For the record, Excelebration, winner of the Group 1 Prix du Moulin de Longchamp last September and second to Frankel in the Lockinge, is next in the betting at 6-1.

Earl of Tinsdal, a Group 1 winner in Germany last year, led throughout Sunday’s Group 1 Gran Premio di Milano at San Siro Racecourse in Milan, Italy, his first major win of 2012.

Ridden by William Buick, Earl of Tinsdal, the 5-2 second choice, won the race over about 1 1/2 miles on turf by 3 1/2 lengths over the mare Quiza Quiza Quiza. Vadamar, the 4-5 favorite, could only finish third in the field of seven.

Earl of Tinsdal, a 4-year-old German-bred by Black Sam Bellamy, was fourth in the Group 2 Gerling Preis in Cologne, Germany, in April.

European Group 1 winners Earl of Tinsdal, Estejo, and Quiza Quiza Quiza are part of a field of nine in Sunday’s Group 1 Gran Premio di Milano at San Siro Racecourse, the first major race of the year for older horses at the Milan, Italy, course.

The Gran Premio di Milano, worth approximately $261,000, is run over about 1 1/2 miles on turf on a right-handed course.

When Charles Hatton, the Daily Racing Form columnist, began calling Gallant Fox’s 1930 run through the Kentucky Derby, the Preakness Stakes, and the Belmont Stakes the Triple Crown, he was mining a term said to have originated in mid-19th century England when a horse named West Australia won the 2000 Guineas, the Derby, and the St. Leger.