4 th Crusade is an eternal stain on Christendom. However the Battle of Manzikert set the decline and fall in motion. Emperor Romanus Diogenes went to fight Alp Arslan, a Seljuk, and was abandoned in the thick of fighting by generals loyal to members of the Court and Anatolian Military Aristocracy. Think Bureaucracy and Military Intelligence abandoning their Commander in Chief to their most hated foe. He had tried to curb the Court's influence and introduce reform to help the small land owning class (bulk of troops, food, taxes) against the wealthy military Aristocracy. From there Central Turkey (manpower, taxes, food) was lost and not even the Comnenus revival could save it.