The traditional definition of the Maghreb — which restricted its scope to the Atlas Mountains and the coastal plains of Morocco, Algeria, Tunisia and Libya — was expanded in modern times to include Mauritania and the disputed territory of Western Sahara.

[7] Before the establishment of modern nation states in the region during the 20th century, the Maghreb most commonly referred to a smaller area, between the Mediterranean Sea and the Atlas Mountains in the south.

As recently as the late 19th century, the term "Maghreb" was used to refer to the western Mediterranean region of coastal North Africa in general, and to Algeria, Morocco, and Tunisia in particular.

Algeria, Libya, Mauritania, Morocco, and Tunisia established the Arab Maghreb Union in 1989 to promote cooperation and economic integration in a common market.

[12] Etymologically, it means both "the western place/land" and "the place where the sun sets", in contrast to the Mashriq, the Fertile Crescent and eastern part of the Arab world.

[14] This constituted the earliest documented differentiation between the terms Maghreb and Gharb (Muslim lands west of the Abbasid capital, Baghdad).

[15] The term Maghrib is used in opposition to Mashriq in a sense near to that which it had in medieval times, but it also denotes simply Morocco when the full al-Maghrib al-Aqsa is abbreviated.

Around 3,500 BC, these changes in the tilt of the Earth's orbit appear to have caused a rapid desertification of the Sahara region[17] forming a natural barrier that severely limited contact between the Maghreb and sub-Saharan Africa.

The main Berber and Phoenician settlements centered in the Gulf of Tunis (Carthage, Utica, Tunisia) along the North African littoral, between the Pillars of Hercules and the Libyan coast east of ancient Cyrenaica.

Rome was greatly helped by the defection of Massinissa (later King of Numidia, r. 202 – 148 BC) and of Carthage's eastern Numidian Massylii client-allies.

[29] These Bedouin tribes accelerated and deepened the Arabization process, since the Berber population was gradually assimilated by the newcomers and had to share with them pastures and seasonal migration paths.

Most notable were the moriscos and muladies, that is, the indigenous Spaniards (Moors) who were forcibly converted to Catholicism and later expelled, together with ethnic Arab and Berber Muslims, during the Spanish Catholic Reconquista.

Jewish communities continued to develop throughout the Roman period in present-day Tunisia, Algeria, and Morocco, with evidence of their existence during the early centuries CE.

[48] During the early Muslim era, Jews flourished in major urban centers such as Kairouan, Fez, and Tunis, despite facing intermittent persecution, notably under the Almohads.

[49] The influx of Sephardic Jews from Spain and Portugal, fleeing pogroms, forced conversions and expulsions in the 14th to 16th centuries, further augmented the Jewish presence in North Africa.

In Algeria especially, a large European minority, known as the "pied noirs", immigrated to the region, settling under French colonial rule in the late 19th century.

Haplogroup J1 is the second most frequent among Maghrebi groups and is more indicative of Middle East origins, and has its highest distribution among populations in Arabia and the Levant.

Due to the distribution of E-M81(E1b1b1b1a), which has reached its highest documented levels in the world at 95–100% in some populations of the Maghreb, it has often been termed the "Berber marker" in the scientific literature.

[citation needed] The second most common marker, Haplogroup J, especially J1,[55][56] which is typically Middle Eastern and originates in the Arabian peninsula, can reach frequencies of up to 35% in the region.

[65] Recent genome-wide analysis of North Africans found substantial shared ancestry with the Middle East, and to a lesser extent sub-Saharan Africa and Europe.

The recent gene flow caused by the Arab migrations to the Maghreb increased genetic similarities between Maghrebis and Middle Easterners.

This theory is based on the social and linguistic structures of the Amazigh cultures that antedated all Egyptian and eastern Asian, northern Mediterranean, and European influences.

Historic records of religion in the Maghreb region show its gradual inclusion in the Classical World, with coastal colonies established first by Phoenicians, some Greeks, and later extensive conquest and colonization by the Romans.

There are also Christian communities of Berber or Arab descent in Greater Maghreb,[83] made up of persons who converted mostly during the modern era, or under and after French colonialism.

Due to the exodus of the pieds-noirs in the 1960s, more North African Christians of Berber or Arab descent now live in France than in Greater Maghreb.

[83] Recently, the Protestant community of Berber or Arab descent has grown significantly as additional individuals convert to Christianity, especially to Evangelicalism.

The earliest documented Jewish presence in the Maghreb dates to the third century BCE, with Jews being settled in eastern Libya by the Ptolemaic rulers of Egypt.

[47] During the Roman Empire, Jewish communities expanded across the Maghreb, with archaeological evidence, including synagogues and inscriptions, indicating their presence in what are now Tunisia, Algeria, and Morocco from the early centuries CE.

[49] In the 14th to 16th centuries, the Maghreb experienced an influx of Jews fleeing from Spain and Portugal due to growing persecution and the Spanish Inquisition.

[50] In the 10th century, as the social and political environment in Baghdad became increasingly hostile to Jews, some Jewish traders emigrated to the Maghreb, especially Kairouan, Tunisia.