Ottoman Coat of Arms

The Ottoman military was a complex system of recruiting and fief-holding. In the Ottoman army, light cavalry long formed the core and they were given fiefs called timars granted to them by the sultan and commanded the personal loyalty of the peasants who worked the land. The Spahis were organized in the 14th century on a feudal basis. The Spahis were entitled to all income from the fief in return for military service to the sultan. Until the mid-16th century they provided the bulk of the Ottoman army. 

Committed to the tradition of light cavalry, they were slow to adopt firearms, whose development made the cavalry less important. 

Cavalry used bows and short swords and made use of nomad tactics similar to those of the Mongol Empire. The Ottoman army was once among the most advanced fighting forces in the world being one of the first to employ muskets. The famous Janissary corps provided elite troops and bodyguard for the sultan. However, after the 17th century, the Ottoman could no longer produce a modern fighting force because of lack of reforms, mainly because of the corrupted Janissaries.

The abolition of the corps in 1826 was not enough and in the war against Russia, the Ottoman Empire severely lacked modern weapons and technologies.

They remained politically important until Mahmud II revoked their fiefs in 1828, two years after he crushed the Janissaries with modern artillery in his effort to build a modern army. In the French army certain Algerian and Senegalese cavalry units were also called Spahis. The term is sometimes spelled Sepahis.

Turkish Spahisi Cavalry - 1595