How did Numidia and Mauritania become part of the Roman Empire?

The integration of Numidia and Mauretania into the Roman Empire occurred through a combination of military conquest, political maneuvering, and the eventual annexation of client kingdoms.

Numidia

Numidia’s path to becoming a Roman province was gradual:
* Client Status: Following the Second Punic War, Masinissa established a powerful kingdom as a Roman ally, turning the region toward Carthaginian and Roman cultural influences.12
* Conflict and Annexation: After the Jugurthine War, Rome exerted tighter control through client kings. The kingdom finally fell in 46 BCE after Juba I supported the losing side in the Roman civil war against Julius Caesar.321
* Provincial Formation: Caesar created the province of Africa Nova from Numidian territory, which Augustus later amalgamated with the original province of Africa.12

Mauretania

Mauretania’s transition was primarily diplomatic before becoming administrative:
* Vassalage: Kings of Mauretania became Roman vassals starting in the late 2nd century BCE.4
* Annexation: In 33 BCE, Bocchus II bequeathed his kingdom to Rome, though Augustus initially preferred to install Juba II as a client king.1
* Provincial Division: Following the execution of the last king, Ptolemy, by Caligula in 40 CE, the region was annexed and formally divided by Claudius into two provinces: Mauretania Tingitana and Mauretania Caesariensis.14