The presence of more than one haseki was a significant change in the reigns of Murad and Ibrahim, signaling that the age of the favorite was coming to an end. In this period the meaning of the title haseki begins to shift from a single "favorite" to something more general like "royal consort," similar to the earlier khatun. This title deflation was a sign of the return of an earlier principle of royal reproduction, that of a number of concubines roughly equal in status. That other concubines were no longer consigned to languish in the shadow of a favorite is suggested not only by the fact that each was endowed with the title haseki but also that their stipends were on the whole equal. — Leslie P. Peirce, The Imperial Harem: Women and Sovereignty in the Ottoman Empire
The Hasekis of the Ottoman Empire - requested by anon
Sources:
-The Structure of the Ottoman Dynasty, by A. D. Alderson
-Bu Mülkün Kadın Sultanları, by Necdet Sakaoğlu
-Padişahların Kadınları ve Kızları, by M. Çağatay Uluçay