He was sired by August Belmont Jr.'s American-bred St Leger winner Tracery out of Countess Zia, a mare owned by Lord Wavertree.

In 1915, Wavertree donated all his bloodstock, including the pregnant Countess Zia, to the British Government, and The Panther was foaled the following spring at the National Stud.

He showed promise in finishing a close second to Galloper Light, a colt who went on to win the Grand Prix de Paris.

At the next Newmarket meeting he recorded his first win when he beat a field of thirty opponents very easily[4] by eight lengths in the Bartlow Plate.

[12] His task appeared to have been made easier when Stefan the Great, who had been considered his most serious rival,[13] failed to recover from injury[14] and was withdrawn from the race.

He started badly then rushed up to join the leaders after four furlongs before dropping away quickly and finishing ninth behind Grand Parade.

[16] A later explanation was that The Panther was distracted by the presence in the pre-race parade of a mounted policeman riding a mare which was described as being "in a condition to upset any stallion" (in season).

[20] After showing good early speed however, The Panther dropped away quickly and finished unplaced behind Buchan, leading The Sportsman to suggest that he was deficient in either ability or courage.