Complex sentence: He was the last pharaoh to do so, his successors Djedkare Isesi and Unas abandoning this practice as the cult of Ra declined at the expense of that of Osiris.
Split into simpler sentences: He was the last pharaoh to do so. His successors, Djedkare Isesi and Unas, abandoned this practice as the cult of Ra declined at the expense of that of Osiris.