An estimate of the population of all Ukrainian oblasts and other territories was recorded in 2012. The war in Donbas, beginning in the spring of 2014, caused an estimated 1.5 million people from Donetsk Oblast and Luhansk Oblast to flee to Russia or other parts of Ukraine. Since the annexation of Crimea by the Russian Federation in March 2014, Crimea and Sevastopol have been disputed between Russia and Ukraine, with Russia signing a treaty of accession on 18 March 2014 with the self-declared independent Republic of Crimea, absorbing it into the Russia, though this is not recognised by Ukraine or most of the international community.