The right bank of Amu Darya or southern Karakalpakstan in the first half of the 1st millennium BC was a flourishing oasis with towns and complex irrigation patronized by the kings of ancient Khorezm. Over millennia Khorezmians had controlled northern trade routes of the Silk Road. Khorezm had its own calendar starting from the accession of Siyavushid dynasty in the 13th century BC, and its own writing originated from the 5th–4th centuries BC.
In the middle of the 6th century BC Khorezm was conquered by Persian kings of the Achaemenid dynasty, but from the middle of the 4th century BC it regained independence under the rule of Siyavushids. One of them, King Farasman in 328 BC sent an embassy to Alexander the Great. On the Akshakhan Kala settlement(42 hectares) the remains of the capital of Khorezm were found dated to 5th–2nd centuries BC with a gallery of portraits of Siyavushids in the royal palace.
During the second half of the 2nd century BC the Yuezhi dynasty comes into power, their grand royal residence was located on the site of Toprak Kala (120 hectares) at the 2nd–3rd centuries. Since the beginning of the 4th century Khorezm was ruled by the Afrighids dynasty, their capital was Kyat (a settlement near Beruni town). From the 8th century as a result of the Arab conquest Khorezm became a part of the Islamic world.
Due to the tragic environmental changes connected with the cycles of the Aral Sea and Amu Darya River, the ancient water supply system gradually went to decline starting from the 12th–14th centuries. The channels dried up, people left the cities and the desert swallowed the oasis. Today, only majestic ruins of the ancient and medieval towns, castles and chateaus remind of the ancient culture.