The first traces of human presence in the area dates to 35-150 thousand years ago. Early evidence was found on the surface of ancient river gravels Gyrshelunki near the city of Chita, near Ust-Menza on the Chikoy River. Mongolic-related Slab Gravecultural monuments are found in Baikal territory. The territory of Zabaykalsky Krai has been governed by the Xiongnu Empire and Mongolian Xianbei state, Rouran Khaganate, Mongol Empire and Northern Yuan. Medieval Mongol tribes like Merkit, Tayichiud, Jalairs and Khamag Mongols inhabited in the krai. In the 17th century, some or all of Mongolic-speaking Daurs lived along the Shilka, upper Amur, and on the Bureya River. They thus gave their name to the region of Dauria, also called Transbaikal, now the area of Russia east of Lake Baikal. Today Buryat-Mongols remained in the territory of the krai. Preliminary work on the unification of the Chita Oblast and Agin-Buryat Autonomous Okrug was started at the level of regional authorities in April 2006. The governor of Chita Oblast Ravil Geniatulin, mayor of the Agin-Buryat Autonomous Okrug Bair Zhamsuyev, head of the regional parliament Anatoly Romanov, and Dashi Dugarov sent a letter to the President of Russia, Vladimir Putin, and on November 17, 2006, he supported the initiative. A referendum on unification took place on March 11, 2007. In Chita Oblast, "yes" was the predominant answer to the following question: In Chita Oblast, 90.29% of the voters voted for the union versus - 8.89% who voted against it. 72.82% of the electorate participated. In the Aga Buryat Autonomous Region 94% voted for the union versus - 5.16%. 82.95% of the electorate voters participated. On July 23, 2007, Russian President Vladimir Putin signed a federal constitutional law "On Establishment in the Russian Federation of a new subject of the Russian Federation in the merger of Chita Oblast and Agin-Buryat Autonomous Okrug", adopted by the State Duma on July 5, 2007. and approved by the Federation Council on July 11, 2007.
Population: According to the 2010 Census, Russians made up 89.9% of the population while Buryats were 6.8%. Other significant groups were Ukrainian, Tatars, Belorussian, Azeri, Evenks. 19,981 people were registered from administrative databases, and could not declare an ethnicity. It is estimated that the proportion of ethnicities in this group is the same as that of the declared group.
As of a 2012 survey 25% of the population of Zabaykalsky Krai adheres to the Russian Orthodox Church, 6.25% to Buddhism, 6% declares to be generically unaffiliatedChristian, 2% is an Orthodox Christian believer without belonging to any church or being member of other Orthodox churches. In addition, 28% of the population declares to be "spiritual but not religious", 17% to be atheist, and 16.15% follows other religion or did not give an answer to the survey.
