The bulk of the army consisted of the provincial cavalry forces, known as timarli sipahis (timariot) after the military fiefs (timar) through which Istanbul compensated them for their service.
Hellie suggests that the pomest'e middle service class was about 25,000 strong between 1550 and 1650, which is close to the size of the timariot sipahis (23,000) in the 1520s.
By the 1390s, the Ottoman government employed on a permanent basis gunners who manufactured and handled firearms, remunerating them through military fiefs (timariot topcus).
Like its middle-service pomest'e counterpart in Muscovy, the timariot sipahi cavalry declined in military importance, and its number in campaigns dropped accordingly.
By the end of the 17th century, only a small portion of the timariot army could actually be mobilized.
(84) Geza David and Pal Fodor, "Changes in the Structure and Strength of the Timariot Army from the Early Sixteenth to the End of the Seventeenth Century," Eurasian Studies Yearbook 4, 2 (2005): 177, 188.
Together with the ulema, they formed an administrative layer "locally reproducing the political and ideological functions of the state." (7) This prevented the temporary timariot
recruits from both merging with civil society and developing potentially decentralizing transcendental cults.