The Slavs are an Indo-European ethno-linguistic group living in Central Europe, Eastern Europe, Southeast Europe, North Asia and Central Asia, who speak the Indo-European Slavic languages, and share, to varying degrees, certain cultural traits and historical backgrounds. From the early 6th century they spread to inhabit most of Central and Eastern Europe and Southeast Europe. Slavic groups also ventured as far as Scandinavia, constituting elements amongst the Vikings; while at the other geographic extreme, Slavic mercenaries fighting for the Byzantines and Arabs settled Asia Minor and even as far as Syria. Later, East Slavs (specifically, Russians and Ukrainians) colonized Siberia and Central Asia. Every Slavic ethnicity has emigrated to other parts of the world. Over half of Europe's territory is inhabited by Slavic-speaking communities.Modern nations and ethnic groups called by the ethnonym Slavs are considerably diverse both genetically and culturally, and relations between them – even within the individual ethnic groups themselves – are varied, ranging from a sense of connection to mutual feelings of hostility.Present-day Slavic people are classified into West Slavic (chiefly Poles, Czechs and Slovaks), East Slavic (chiefly Russians, Belarusians, and Ukrainians), and South Slavic (chiefly Bosniaks, Serbs, Croats, Bulgarians, Macedonians, Montenegrins, and Slovenes). For a more comprehensive list, see the ethnocultural subdivisions.