The second half of 16th and early 17th centuries was an important landmark in the history of the peoples of the Northeast Caucasus. That was when essential events greatly influenced the subsequent course of historical processes. Chechens continued to move from the mountains to the plains. Kumyks are settling in the Terek-Sulak interfluve, which gives birth to the renowned Endirean princedom in the region's history. This is where Chechens (Akkits-Aukhovs) and Kumyks (Northern Kumyks) are further divided into separate ethno-territorial groups. The social terminology of the northern Kumyks features the Sala-uzdeni nobility. The emergence of the term among the northern Kumyk is connected with the Sala (Saloi) Chechen ethnic group closely linked with the early stage of the development of the Endirean princedom, headed by Sultan-Makhmud. In recognition of their merits, Sultan Mahmud conferred numerous rights and privileges on members of the Sala ethnic group, from whom he found support and encouragement in his difficult time. This was the basis of the formation of a new higher nobility, the Sala-uzdeni, which subsequently came to include members of various ethnic groups. The Chechens continued to fully support Sultan-Mukhmud during military and political events of the first quarter of the 17th century, when he was opposed by Dagestani feudals and Russian troops of Terek.