Tranquil Star was one of the hardiest and best performed Australian-bred Thoroughbred race-mares. She is the only mare to have won the double of the Caulfield Stakes, now known as the Yalumba Stakes, and the Cox Plate, which is the most prestigious weight-for-age (wfa) race in Australia. Tranquil Star had 111 starts and won over distances ranging from 5 furlongs to 14 furlongs. She was later inducted into the Australian Racing Hall of Fame.

The VRC Champions Stakes, registered as the LKS Mackinnon Stakes, is a Victoria Racing Club Group 1 Thoroughbred horse race run under Weight for Age conditions over a distance of 2000 metres at Flemington Racecourse in Melbourne, Australia on the last day of the Melbourne Cup Carnival, the Saturday after the Melbourne Cup. Total prize money is A$3,000,000.