The shelters found at the Mouilah and Boudghene show evidence of long periods of pre-historic human habitation.

[6] In 1081 or 1082 the Almoravid leader Yusuf ibn Tashfin founded the city of Tagrart ("encampment" in Berber language), just west of Agadir.

[15] In about 1209, the region around Tlemcen was devastated by retreating Almoravid forces, not long before their final defeat by the Almohads at the Battle of Jebel Nafusa in 1210.

[17] The Zayyanid ruler Yaghmurasen Ibn Zyan succeeded in merging Agadir and Tagrart into a single city and gave it the name Tlemcen.

[5] Initially, Yagmurasen resided in the Qasr al-Qadim but he soon moved the seat of power to a new citadel, the Mechouar, towards the mid 13th century.

During this era it was one of the most important economic and cultural centers in the region, alongside other political capitals like Fez, Tunis, and Granada.

[23] African gold arrived in Tlemcen from south of the Sahara through Sijilmasa or Taghaza and entered European hands.

[26] It housed several well-known madrasas and numerous wealthy religious foundations, and became the principal centers of culture in the central Maghreb.

[28] Merchant houses based in Tlemcen, such as the al-Makkari, maintained regular branch offices in Mali and the Sudan.

Tlemcen was a vacation spot and retreat for French settlers in Algeria, who found it far more temperate than Oran or Algiers.

The city adapted and became more cosmopolitan, with a unique outlook on art and culture, and its architecture and urban life evolved to accommodate this new sense.

On January 13 a British and American train patrol engaged in a skirmish with the retreating troops of the Afrika Korps.

[35] Between 1942–1943, before embarking for Italy, the US Army Medical Corps established two fixed hospitals at Tlemcen: 9th Evacuation (as station), 12–26 December 1942.

French Jews of the Alliance Israélite Universelle paid for a local Jewish school, which closed in 1934, perhaps owing to the rise of Fascism.

[38] In 2009 Jordanian sources reported that the Algerian government intended to restore the damaged Jewish tombs at the historic cemetery.

Its textiles and handcrafts, its elegant display of Andalusi culture, and its cool climate in the mountains have made it an important center of tourism in Algeria.