Complex sentence: His grandsire was the noble Herod, the foundation sire through whom Skyscraper was in the direct male line of the Byerley Turk, whike his granddam was Rachel, whose grandsire was the Godolphin Arabian.
Split into simpler sentences: His grandsire was the noble Herod, the foundation sire through whom Skyscraper was in the direct male line of the Byerley Turk. His dam was Rachel, whose grandsire was the Godolphin Arabian.