sentences:  Large-scale population transfers saw the ethnic composition of Abkhazia radically altered, with thousands of ethnic Abkhaz expelled and ethnic Mingrelians brought in to replace them.After the 1917 February Revolution, which ended the Russian Empire, the status of Abkhazia became contested and was unclear.Free from Russian rule, it considered joining the Mountainous Republic of the Northern Caucasus in 1917, but ultimately decided against this due to the distance between Abkhazia and the rest of the groups involved.