When Rome annexed Ptolemy of Mauretania's kingdom, Anfa was incorporated into the Roman Empire by Caligula. But this was done only nominally because the Roman limes was a few dozen kilometers north of the port (the Roman military fortifications of Mauretania Tingitana were just a few kilometers south of the Roman colonia named Sala Colonia). However, Roman Anfa—connected mainly by commerce and by socio-cultural ties to Volubilis ("autonomous" from Rome since 285 AD)—lasted until the 5th century, when Vandals conquered Roman northwestern Africa.