Proto-Berber language reached the stage where these different branches of this language family evolved. From that perspective, Proto-Berber was the first Berber stage to depart from Proto-Afrosiatic in the eighth millennium. It was restructured several times during the almost 10,000 years that separated it from its modern shape, which has preserved few relics. Roger Blench (2018) suggests that Proto-Berber speakers experienced intense language leveling about 2,000 years ago as the Roman Empire was expanding in North Africa. Hence, although Berber had split off from Afroasiatic several thousand years ago, Proto-Berber itself can only be reconstructed to a period as late as 200
Proto-Berber language are the only Berber languages to preserve Proto-Berber *β as β; elsewhere in Berber it becomes "h" or disappears. The Proto-Berber consonantal system reconstructed by Allati (cf. Allati, 2002, 2011) is based on remains from the ancient stages of this language preserved in the ancient toponymical stratas, in Libyan inscriptions and in the modern Berber varieties. It had stops b, t, d, k, g; fricative s; nasal n and liquids l, r. The stops of the phonological system have evolved since the proto-Berber stage into variants from which other consonants have been progressively formed (Allati, 2002, 2011). Karl G. Prasse