Latvia as its currency since 1 January 2014, replacing the Latvian lats. The name "Latvija" is derived from the name of the ancient Latgalians, one of four Indo-European Baltic tribes (along with Couronians, Selonians and Semigallians), which formed the ethnic core of modern Latvians together with the Finnic Livonians. Henry of Latvia coined the latinisations of the country's name, "Lettigallia" and "Lethia", both derived from the Latgalians. The terms inspired the variations on the country's name in Romance languages from "Letonia" and in several Germanic languages from "Lettland". Around 3000 BC, the proto-Baltic ancestors of the Latvian people settled on the
Currency mostly paper, but Australia's Commonwealth Scientific and Industrial Research Organisation developed the world's first polymer currency in the 1980s that went into circulation on the nation's bicentenary in 1988. Now used in some 22 countries (over 40 if counting commemorative issues), polymer currency dramatically improves the life span of banknotes and prevents counterfeiting. Currency use is based on the concept of lex monetae; that a sovereign state decides which currency it shall use. Currently, the International Organization for Standardization has introduced a three-letter system of codes (ISO 4217) to define currency (as opposed to simple names or currency signs), in