How relevant were Sipahis in Ottoman history? Janissaries organized

>>3032452
Unlike the Janissaries, whose existence was brought upon by the Ottoman state and only the Ottoman state, many Sipahis were similar to European knights in that they formed a distinct class of hereditary landholding petty nobles whose main purpose was as an elite force for war. That is probably why you haven't heard much about them, because they existence isn't really that remarkable, and is completely to be expected.

>>3034081
Sipahis weren't hereditary nobles. The land they had wasn't even really owned by them, but by the state. The sultan granted them land in return for service but he could also retract it from them whenever and however he felt like.