"Photian" Schism & Cardinal System

The western christians "blame" the east for the schism. And the eastern christians explain the so-called "photian schism". You are welcome to explore both sides. For the western side I recommend Francis Dvornik: The Photian Schism: History and Legend. And for the eastern orthodox I recommend any eastern bishop or theologian; especially if you investigate Councils of Constantinople IV and V. Doctrines of the eastern rite and western rite used as strategic influence over political campaigns (wars over land and supervision of authority). Within 100 years there would be a political shift between western and eastern authorities. Specifically in the west, German kings began directly appointing popes in Rome around the mid-11th century, starting with Holy Roman Emperor Henry III in 1046. This period of imperial dominance over papal appointments was brief, as the Gregorian Reform in the mid-11th century, beginning with Pope Nicholas II in 1059, ultimately shifted the power to elect the pope to the College of Cardinals. The organization and role of the College of Cardinals have changed since the college’s creation in 1150. Prior to this innovation between 900AD to 1059AD, Popes (Archbishops) had always been selected by a council of Church fathers, without a need for Cardinals. For more info, see the Investiture Controversy. Otherwise see an Orthodox memoir through St Photius and his commemoration. One site is https://pravoslavie.ru/97929.html Also for context I recommend this movie. https://youtu.be/nXuqqy2ZWdE?si=_oAwSQfES7R1fAjh