Scythia (ˈsɪðiə, ˈsɪθiə;) or Scythica (ˈsɪðikə, ˈsɪθikə) was the Graeco-Roman name for a region of Eastern Europe corresponding to the Pontic steppe, which in antiquity was inhabited by the Scythians, who were an ancient Eastern Iranian equestrian nomadic people. The names and are themselves Latinisations of the Ancient Greek names (Σκυθια) and (Σκυθικη), which were themselves derived from the ancient Greek names for the Scythians, Skuthēs (Σκυθης) and Skuthoi (Σκυθοι), derived from the Scythian endonym Skuδatā. The territory of the Scythian kingdom of the Pontic steppe extended from the Don river in the east to the Danube river in the west, and covered the territory of the treeless steppe immediately north of the Black Sea's coastline, which was inhabited by nomadic pastoralists, as well as the fertile black-earth forest-steppe area to the north of the treeless steppe, which was inhabited by an agricultural population, and the northern border of this Scythian kingdom were the deciduous woodlands, while several rivers, including Don and Dnipro, flowed southwards across this region and emptied themselves into the Black Sea. Between the 9th and 5th centuries BC, the climate in the steppes was cool and dry, which was a catalyst for the emergence of equestrian nomadic pastoralism in the northern Pontic region. The climate became warmer and wetter during the 5th century BC, which allowed the steppe nomads to move into the steppes proper. In these favourable climatic conditions grass grew abundantly on the treeless steppe and permitted the nomadic Scythians to rear large herds of cattle and horses. The country which the Greeks named (Hulaia), consisting of the region of the lower Dnipro river along the territory of what is modern-day Kherson and the valleys further north along the river, was covered with forests. Conditions in the southern lands near the shores of the Black Sea were propitious for agriculture. Before the arrival of the Scythians, this region of the Pontic Steppe was dominated by the Agathyrsi, who were nomadic Iranian people related to the Scythians.