The largest two cities, the two administrative centers, each have less than 200 thousand residents--not too surprising since less than a million people live in this area.
Western Turkic peoples arrived in the later centruies of the first millenium. Kazakhs and Turkmen are among their descendents, but Oghuz Turks were initially predominant until they moved on. They initially followed their ancient religion, which remembered sacred groves and a myth of the origins of metallurgy. From the 11th century on they steadily adopted Islam.
In the 13th century Mongols conquered all of central Asia, but their local influence was only political until a splinter group of them, the Torghuk, migrated here. They forcibly ejected the Turkmen and many of the Kazakhs, and lived here from 1616 to 1771, whereuon they departed en masse after quarreling with their erstwhile friends, the Russians. The Christian Russians had found alliance with these Lamist Buddhists useful in their wars against Moslem Kazakhs. But Russian influence beyond a few fortresses was minor until the 19th and 20th centuries; it is receding since Kazakhstan gained independence.
north, and east of Atyrau and of northern Mangistau
east of central and southern Mangistau
south of Mangistau
southwest across the Caspian Sea from southern Mangistau
west across the Caspain Sea, and west of western Atyrau
(1) Also transliterated Qazaqstan, Kazakstan or Kazachstan.
(2) Also transliterated as Mankistau, formerly Mangistauz.
(3) Also transliterated as Atirau. Formerly known in transliteration from Russian as Guryevskaya or Gurjevskaja Oblast.