Complex sentence: He was sired by Pleasant Colony, winner of the 1981 Kentucky Derby and Preakness Stakes and out of Payson's mare, Northern Sunset, a granddaughter of the pre-eminent sire of the 20th Century, Northern Dancer.
Split into simpler sentences: He was sired by Pleasant Colony, winner of the 1981 Kentucky Derby and Preakness Stakes. Her dam, Northern Sunset was, a granddaughter of the pre-eminent sire of the 20th Century, Northern Dancer.