The hypothetical ancestral language of the Nostratic family is called Proto-Nostratic. Proto-Nostratic would have been spoken between 15,000 and 12,000 BCE, in the Epipaleolithic period, close to the end of the last glacial period.
The Nostratic hypothesis originates with Holger Pedersen in the early 20th century. The name "Nostratic" is due to Pedersen (1903), derived from the Latin nostrates "fellow countrymen". The hypothesis was significantly expanded in the 1960s by Soviet linguists, notably Vladislav Illich-Svitych and Aharon Dolgopolsky, termed the "Moscovite school" by Bomhard (2008, 2011, and 2014), and it has received renewed attention in English-speaking academia since the 1990s.
The hypothesis is controversial and has varying degrees of acceptance amongst linguists worldwide. In Russia, it is endorsed by a minority of linguists, such as Vladimir Dybo, but is not a generally accepted hypothesis. Allan Bomhard is a supporter, Lyle Campbell a critic. Some linguists take an agnostic view. Eurasiatic, a similar grouping, was proposed by Joseph Greenberg (2000) and endorsed by Merritt Ruhlen: it is taken as a subfamily of Nostratic by Bomhard (2008).
These proposals were taken much further in 1903 when Holger Pedersen proposed "Nostratic", a common ancestor for the Indo-European, Finno-Ugric, Samoyed, Turkish, Mongolian, Manchu, Yukaghir, Eskimo, Semitic, and Hamitic languages, with the door left open to the eventual inclusion of others.
The name Nostratic derives from the Latin word nostrās, meaning 'our fellow-countryman' (plural: nostrates) and has been defined, since Pedersen, as consisting of those language families that are related to Indo-European. Merritt Ruhlen notes that this definition is not properly taxonomic but amorphous, since there are broader and narrower degrees of relatedness, and moreover, some linguists who broadly accept the concept (such as Greenberg and Ruhlen himself) have criticised the name as reflecting the ethnocentrism frequent among Europeans at the time. Martin Bernal has described the term as distasteful because it implies that speakers of other language families are excluded from academic discussion. Even so, the concept arguably transcends ethnocentric associations. (Indeed, Pedersen's older contemporary Henry Sweet attributed some of the resistance by Indo-European specialists to hypotheses of wider genetic relationships as "prejudice against dethroning from its proud isolation and affiliating it to the languages of yellow races".) Proposed alternative names such as Mitian, formed from the characteristic Nostratic first- and second-person pronouns mi 'I' and ti 'you' (exactly 'thee'), have not attained the same currency.
An early supporter was the French linguist Albert Cuny—better known for his role in the development of the laryngeal theory—who published his Recherches sur le vocalisme, le consonantisme et la formation des racines en « nostratique », ancêtre de l'indo-européen et du chamito-sémitique ('Researches on the Vocalism, Consonantism, and Formation of Roots in "Nostratic", Ancestor of Indo-European and Hamito-Semitic') in 1943. Although Cuny enjoyed a high reputation as a linguist, the work was coldly received.