Complex sentence: The chestnut was foaled near Lexington, Kentucky in 1901 by Octagon, out of the English bred Bella Donna (by the Epsom Derby winner Hermit).
Split into simpler sentences: The chestnut was foaled near Lexington, Kentucky, in 1901. She was by Octagon, out of the English-bred Bella Donna (by the Epsom Derby winner Hermit).