 Complete the following phrase:  Sukhumis history can be traced to the 6th century BC, when it was settled by Greeks, who named it Dioscurias. During this time and the subsequent Roman period, much of the city disappeared under the Black Sea. The city was named Tskhumi when it became part of the Kingdom of Abkhazia and then the Kingdom of Georgia. Contested by local princes, it became part of the Ottoman Empire in the 1570s, where it remained until it was conquered by the Russian Empire in 1810. After a period of conflict during the Russian Civil War, it became part of the independent Georgia, which included Abkhazia, in 1918. In 1921, the Democratic Republic of Georgia was 