Complex sentence: The title was first adopted by Robert de Ferrers, 1st Earl of Derby under a creation of 1139, and continued until the 6th Earl forfeited his property toward the end of the reign of Henry III and died in 1279.
Split into simpler sentences: The title was first adopted by Robert de Ferrers, 1st Earl of Derby under a creation of 1139. It continued with the Ferrers family until the 6th Earl forfeited his property toward the end of the reign of Henry III and died in 1279.