The country's native name ''Polska'' is derived from the Lechitic tribe of Western Polans, who inhabited the Warta river basin of present-day Greater Poland region starting in the mid-6th century. The tribe's name itself stems from the Proto-Indo European ''*pleh₂-'' (flatland) and the Proto-Slavic word ''pole'' (field). The etymology eludes to the topography of the region and the flat landscape of Greater Poland. The English name ''Poland'' was formed in the 1560s from Middle High German ''Pole(n)'' and the suffix ''land'', denoting a people or nation. Prior to its adoption, the Latin form ''Polonia'' was widely used throughout medieval Europe.