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 (tributary of the Khilok River) near the city of Chita, near Ust-Menza on the Chikoy River.
Based on toponyms, Zabaykalsky might have once been inhabited by a non documented, extinct Yeniseian language.[12]
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:
Do you agree that the Chita Oblast and Agin-Buryat Autonomous Okrug merged into a new entity of the Russian Federation - Zabaykalsky Krai, which included Agin-Buryat Autonomous Okrug will be an administrative-territorial unit with special status, defined by the charter of the province in accordance with the legislation of the Russian Federation?
In Chita Oblast, 90.29% (535,045 voters) of the voters voted for the union versus - 8.89% (52,698 voters) who voted against it. 72.82% of the electorate participated. In the Aga Buryat Autonomous Region 94% (38,814 voters) voted for the union versus - 5.16% (2129 voters). 82.95% of the electorate voters participated.
On July 23, 2007, Russian PresidentVladimir 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.
Large companies in the region include the Priargunskoe Mining and Chemical Association, Territorial Generating Company №14, Novo-Shirokinsky mine, Kharanorskaya State District Power Plant, Kharanorskiy coal mine.[15]
According to the 2021 Census,[21] Russians made up 89.2% of the population while Buryats were 7.4%. Other significant groups were Armenians (0.3%), Tatars (0.3%), Ukrainians (0.2%), Kyrgyz (0.2%) and Uzbeks (0.2%) . 118,477 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.[22]
As of a 2012 survey[27] 25% of the population of Zabaykalsky Krai adheres to the Russian Orthodox Church, 6.25% to Buddhism, 6% declares to be generically unaffiliatedChristian (excluding Protestant churches), 2% is an Orthodox Christian believer without belonging to any church or being member of other (non-Russian) 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.[27]
^Президент Российской Федерации. Указ №849 от 13 мая 2000 г. «О полномочном представителе Президента Российской Федерации в федеральном округе». Вступил в силу 13 мая 2000 г. Опубликован: "Собрание законодательства РФ", No. 20, ст. 2112, 15 мая 2000 г. (President of the Russian Federation. Decree #849 of May 13, 2000 On the Plenipotentiary Representative of the President of the Russian Federation in a Federal District. Effective as of May 13, 2000.).
^Госстандарт Российской Федерации. №ОК 024-95 27 декабря 1995 г. «Общероссийский классификатор экономических регионов. 2. Экономические районы», в ред. Изменения №5/2001 ОКЭР. (Gosstandart of the Russian Federation. #OK 024-95 December 27, 1995 Russian Classification of Economic Regions. 2. Economic Regions, as amended by the Amendment #5/2001 OKER. ).
^Edward Wajda (2018). "Yeniseian and Dene Hydronyms". In Gary Holton; Thomas F. Thornton (eds.). Language and Toponymy in Alaska and Beyond: Papers in Honor of James Kari. Honolulu: University of Hawai‘i Press. pp. 183–201. hdl:10125/24847. ISBN9780997329544.
Законодательное Собрание Забайкальского края. Закон №125-ЗЗК от 17 февраля 2009 г. «Устав Забайкальского края», в ред. Закона №1307-ЗЗК от 25 марта 2016 г «О внесении изменения в статью 52 Устава Забайкальского края». Вступил в силу через десять дней после дня официального опубликования. Опубликован: "Забайкальский рабочий", №30, 18 февраля 2009 г. (Legislative Assembly of Zabaykalsky Krai. Law #125-ZZK of February 17, 2009 Charter of Zabaykalsky Krai, as amended by the Law #1307-ZZK of March 25, 2016 On Amending Article 52 of the Charter of Zabaykalsky Krai. Effective as of the day which is ten days after the day of the official publication.).
Федеральный конституционный закон №5-ФКЗ от 21 июля 2007 г. «Об образовании в составе Российской Федерации нового субъекта Российской Федерации в результате объединения Читинской области и Агинского-Бурятского автономного округа». (Federal Constitutional Law #5-FKZ of July 21, 2007 On the Establishment Within the Russian Federation of a New Federal Subject of the Russian Federation as a Result of the Merger of Chita Oblast and Agin-Buryat Autonomous Okrug. ).