During their rule in Egypt and Syria (1250–1517), the Mamluks showed a certain ambiguity in their attitude toward the sultanate including its rules of succession and the ruler's source of power. This ambiguity has led to a variety of opinions about the nature of the Mamluk Sultanate in scholarly works on Mamluk history. David Ayalon implies, in “The Circassians in the Mamluk Kingdom,” that the principle of heredity was recognized to various degrees in the Mamluk state, although it was weak during the Bahri period and altogether abandoned during the Circassian period. In “From Ayyubids to Mamluks,” Ayalon confirms that when the Mamluks came to power they had not “ever dreamt of creating a non-hereditary sultan's office” because most of the Bahri period was ruled by the Qalaʾunid dynasty. When nonhereditary rule came about, at least in the Bahri period, it was without any form of planning. In his “Mamluk Military Aristocracy: A Non-Hereditary Nobility,” Ayalon stresses that even during pre- and post-Qalaʾunid times the sultan's office was only nonhereditary to a certain extent and that “throughout the history of the Mamluk Sultanate there is not the slightest mention of the non-hereditary character of the sultan's office, or of the intention of turning it into such.”