http://www.bloodhorse.com/horse-raci...american-roots

I found this particularly interesting:
Bred in Kentucky by Khaled Abdullah’s Juddmonte Farms, Danehill is both a grandson and an equine “cousin” of Northern Dancer. By Northern Dancer’s great son Danzig, Danehill was the first foal of Razyana, by His Majesty, a daughter of Northern Dancer’s half sister Spring Adieu, by Buckpasser. That meant that Danehill was inbred 3x3 to Northern Dancer’s dam Natalma, by Native Dancer.

It also meant that Danehill inherited Natalma’s conformation flaw, but while Natalma was slightly back in her left knee, Danehill was clearly back in both knees. Fortunately for the Thoroughbred breed, he also inherited the extraordinarily robust body, muscularity, and constitution of Native Dancer.