She was the WWII battler that raced 111 times and won many a prestigious race, including the McKinnon 3 times

Tranquil Star was a highly resilient and accomplished Australian-bred Thoroughbred race mare who demonstrated exceptional performances during the challenging era of World War II. 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 race in Australia. Tranquil Star had 111 starts and won over distances ranging from 5 furlongs (1000 metres) to 14 furlongs (2800 metres). She began racing in 1939 as a two-year-old and did not retire until 1946 when she competed as an eight-year-old, averaging nearly 16 starts per season.

She was bred by Messrs H. G. Raymond and H. B. Ranken at St Albans Stud near Geelong, Victoria and was by the good imported sire, Gay Lothario (sire of winners of £266,000), her dam was the non-winner, Lone Star, who was by a good sire in Great Star (GB). Tranquil Star was a sister to the non-stakes-winners, Sun Beau (four wins), Paringa (two wins), Flighty (unplaced) and The Ritz (six wins), who were indifferent racehorses. She was also a half-sister to Only Star, by Enfield, who was unable to win a race in 13 starts. Tranquil Star descended from Daffodils Dam through Lady Vivian (GB), who were from the Bruce Lowe family. Tranquil Star was sold at Mackinnon and Cox's 1939 yearling sales and was purchased by the partners Messrs R. Cobden and T. G. Jones for 600 guineas.

She won the W.S. Cox Plate for the first time as a five-year-old in 1942. When she won it again in 1944 whilst being steered by Scobie Breasley, she became the first seven-year-old mare to win the race, an accomplishment that would not be matched until Makybe Diva took the post in 2005. She had a bit of a slow start as a two-year-old, winning twice from 13 starts, adding four second place finishes. When she raced as a three-year-old, she started to win big races, including the Edward Manifold Stakes, the St. George Stakes, St. Leger Stakes, and the Chipping Norton Stakes. As a four-year-old, she won twice in 21 attempts, posting seconds in the Underwood Stakes and the Cox Plate.

Along with the Cox Plate win in the 1942/43 season, she won the Caulfield Cup where she beat three horses, Colonus, Skipton and Dark Felt that had won the Melbourne Cup. That would have to be considered her best season, with six major wins. She won only once as a six-year-old, the season where she broke her jaw in her final race. In addition to the aforementioned second Cox Plate win in the 1944/45 season, she won the Mackinnon Stakes for the second time and also won the Memsie Stakes. Tranquil Star won her third Mackinnon Stakes in her final season as an eight-year-old. One of the horse she beat was 2007 Hall of Fame inductee Flight.

Tranquil Star produced nine foals. Her daughter Tranquil Dawn was the fifth dam of the 2002 Golden Slipper winner, Calaway Gal. Her colt Tranquil Sun (by Helios) won seven races in Melbourne. Another colt by Helios, Tranquil Glow, won 11 races, 9 of them steeplechases. In her last effort in 1956, she foaled Night Ride by Landau, a five-race winner.

RACE RECORD - 111: 23-20-12

EARNINGS - £26,690

Edward Manifold Stakes (1940)

St George Stakes (1941, 1944, 1945)

VRC St Leger (1941)

Chipping Norton Stakes (1941)

LKS Mackinnon Stakes (1942, 1944, 1945)

Alister Clark Stakes (1942)

Caulfield Stakes (1942)

Caulfield Cup (1942)

W S Cox Plate (1942, 1944)

Memsie Stakes (1945)

William Reid Stakes (1946)