Complex sentence: He is the oldest living member of the Rockefeller family and family patriarch since July 2004, the only surviving child of John D. Rockefeller, Jr. and Abby Aldrich Rockefeller, and the only surviving grandchild of John D. Rockefeller and Laura Spelman Rockefeller.
Split into simpler sentences: He is the oldest living member of the Rockefeller family and family patriarch since July 2004. Rockefeller is also the only surviving child of John D. Rockefeller, Jr. and Abby Aldrich Rockefeller, and the only surviving grandchild of John D. Rockefeller and Laura Spelman Rockefeller.