Bred by J. C. Hill, Gallinule was the third foal of his dam Moorhen and a half-brother to the useful stallion Pioneer (br c 1886 Galopin).

Without doubt his most famous offspring was Pretty Polly (ch f 1901) who galloped off with three classics victories, the One Thousand Guineas, the Oaks and the St. Leger Stakes in her illustrious career.

Sired six Irish Derby winners Carrigavalla (b c 1898), Gallinaria (ch f 1897), Gulsalberk (b c 1893), Noble Howard (ch c 1895), Oppressor (br c 1896) and Port Marnock (br c 1892) and the German Derby winner Chilperic (ch c 1908).

Aside from Pretty Polly, he got the St. Leger winners Night Hawk (bbr c 1910) and Wildfowler (ch c 1895), and the German St. Leger winner Hammurabi (ch c 1903).

He got the Two Thousand Guineas Stakes winner Slieve Gallion (bbl c 1904).

He got the Irish Oaks winner Dabchick (bl f 1894) and the German Oaks winner Waldkatze (ch f 1905).

Some of his more successful sons at stud include White Eagle (ch c 1905), Torloisk (ch c 1912), Santry (br c 1901), Lesterlin (br c 1892), General Peace (br c 1894) and Fariman (b c 1900).