The Indo-European languages are a language family of several hundred related languages and dialects.
There are about 445 living Indo-European languages, according to the estimate by Ethnologue, with over two thirds (313) of them belonging to the Indo-Iranian branch. The Indo-European languages with the greatest numbers of native speakers are Spanish, English, Hindustani (Hindi/Urdu), Portuguese, Bengali, Punjabi, and Russian, each with over 100 million speakers, with German, French, Marathi, Italian, and Persian also having more than 50 million. Today, 46% of the world's population (3.2 billion) speaks an Indo-European language as a first language, by far the highest of any language family.
The Indo-European family includes most of the modern languages of Europe. The language family is also represented in Asia with the exception of East and Southeast Asia. It was prominent (alongside non-Indo-European languages) in ancient Anatolia (present-day Turkey), the ancient Tarim Basin (present-day Northwest China) and most of Central Asia until the medieval Turkic and Mongol invasions. Outside Eurasia, Indo-European languages are dominant in the Americas and much of Oceania and Africa, having reached there through colonialism during the Age of Discovery and later periods. Indo-European languages are also most commonly present as minority languages or second languages in countries where other families are dominant.
With written evidence appearing from the Bronze Age in the form of Mycenaean Greek and the Anatolian languages Hittite and Luwian, the Indo-European family is significant to the field of historical linguistics as possessing the second-longest recorded history, after the Afroasiatic family in the form of the Egyptian language and the Semitic languages of the Near East. In addition, certain extinct language isolates of the Near East and Anatolia, such as Sumerian, Elamite, Hurrian, Hattian, Gutian and Kassite are also recorded earlier than any Indo-European tongue.
All Indo-European languages are descendants of a single prehistoric language, reconstructed as Proto-Indo-European, spoken sometime in the Neolithic era. Although no written records remain, aspects of the culture and religion of the Proto-Indo-Europeans can be reconstructed from the related cultures of ancient and modern Indo-European speakers who continue to live in areas where the Proto-Indo-Europeans migrated from their original homeland. Several disputed proposals link Indo-European to other major language families. Although they are written in the Semitic Old Assyrian language and with the use of the Cuneiform script of Mesopotamia, the Hittite words and names found in the texts of the Assyrian colony of Kültepe in eastern Anatolia are the oldest record of any Indo-European language.
During the nineteenth century, the linguistic concept of Indo-European languages was frequently used interchangeably with the racial concepts of Aryan and Japhetite.