Nevertheless, the region was the focus of ever-increasing disputes between the native Kazakh emirs and the neighbouring Persian-speaking peoples to the south. At its height, the Khanate would rule parts of Central Asia and control Cumania. By the early 17th century, the Kazakh Khanate was struggling with the impact of tribal rivalries, which had effectively divided the population into the Great, Middle and Little (or Small) hordes ("jüz"). Political disunion, tribal rivalries, and the diminishing importance of overland trade routes between east and west weakened the Kazakh Khanate. Khiva Khanate used this opportunity and annexed Mangyshlak Peninsula. Uzbek rule there lasted two centuries until the Russian arrival.