During the 16th century the institutions of society and government that had been evolving in the Ottoman dominions for two centuries reached the classical forms and patterns that were to persist into modern times. The basic division in Ottoman society was the traditional Middle Eastern distinction between a small ruling class of Ottomans (Osmanlı) and a large mass of subjects called rayas (reʿâyâ). Three attributes were essential for membership in the Ottoman ruling class: profession of loyalty to the sultan and his state; acceptance and practice of Islam and its underlying system of thought and action; and knowledge and practice of the complicated system of customs, behaviour, and language known as the Ottoman Way. Those who lacked any of those attributes were considered to be members of the subject class, the “protected flock” of the sultan.