Complex sentence: It was later passed to successively Golden Horde, Nogai Horde, Uzbek Khanate and Kazakh Khanate, but its population was decreased after gradual drying of the steppe and Kalmyk raids began in 1620.
Split into simpler sentences: It was later passed to successively Golden Horde, Nogai Horde, Uzbek Khanate and Kazakh Khanate. But, its population was decreased after gradual drying of the steppe and Kalmyk raids, began in 1620.