Railways with a railway track gauge of 5 ft (1,524 mm) first appeared in the United Kingdom and the United States. This gauge became commonly known as Russian gauge because the government of the Russian Empire later chose it in 1843 — former areas of the Empire have inherited this standard. In the 1960s Soviet Railways re-defined the gauge as 1,520 mm (4 ft 11+27⁄32 in). The primary countries using the gauge include Russia, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan, Armenia, Azerbaijan, Georgia, Belarus, Moldova, Ukraine, Estonia, Latvia, Lithuania, and Finland.