The annexations come after pro-Russian authorities in all four territories held referendums on their union with Russia, 23-27 September. The votes were held without an election campaign, under military occupation in the midst of an armed conflict, and with part of the population having been previously displaced —this is why the vast majority of countries and international organisations have not recognised the polls as valid.
Official results made public by the pro-Russian authorities showed “yes” votes for annexation reached 87% in Kherson, 93% in Zaporizhzhia, 98% in Luhansk, and 99% in Donetsk.
The annexation was announced by Putin himself on 30 September, shortly after he had recognised Kherson and Zaporizhzhia as independent states. The Donetsk and Luhansk republics, self-proclaimed independent in 2014, had been recognised by the Kremlin last February.
Both chambers of the Russian parliament ratified the annexation of the four territories on 3 and 4 October.
The same route was used by Russia to annex Crimea in 2014.
Russia not fully in control of the four territories
The Russian army controls virtually the entire territory of Lugansk, 90% of Kherson, 70% of Zaporizhzhia —but not its namesake capital— and approximately 50% of Donetsk. In the last two weeks, the Ukrainian army has regained ground in Luhansk and Kherson. Russia has not clarified which borders it considers official in Kherson and Zaporizhzhia.