Complex sentence: After his death in 1975, Albert passed Althorp to his son Edward John, 8th Earl Spencer, who then left it to the current owner Charles Spencer, 9th Earl Spencer after his death in 1992.
Split into simpler sentences: After his death in 1975, Albert passed Althorp to his son Edward John, 8th Earl Spencer. Edward left the estate to his son and the current owner Charles Spencer, 9th Earl Spencer after his death in 1992.