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 most widely spoken Indo-European languages by native speakers are Spanish, Hindustani (Hindi-Urdu), English, 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, nearly 42% of the human 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; notable exceptions include Hungarian, Turkish, Finnish, Estonian, Basque, Maltese, and Sami. The Indo-European family is also represented in Asia with the exception of East and Southeast Asia. It was predominant 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 during the Age of Discovery. 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 since the Bronze Age in the form of the Anatolian languages and Mycenaean Greek, the Indo-European family is significant to the field of historical linguistics as possessing the second-longest recorded history, after the Afroasiatic family, although certain language isolates, such as Sumerian, Elamite, Hurrian, Hattian, and Kassite are recorded earlier.
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 also be reconstructed from the related cultures of ancient and modern Indo-European speakers who continue to live in areas to 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 Semitic Old Assyrian, the Hittite loanwords and names found in the Kültepe texts 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.