Legio XV Primigenia was apparently raised by Caligula for his planned but never executed invasion of Britain. Claudius may have named the formation for Fortuna Primigenia after succeeding Caligula in AD 41. Its number probably reflected the recruiting ground of the existing Legio XV Apollinaris at Mainz, and by AD 46 the new legion had moved to Vetera on the lower Rhine. The revolt led by Civilis shattered the legion in AD 69-70, after which Vespasian abolished it.
Notable Point · 39:10-40:03
Legio XV Primigenia from Caligula's invasion plan to Vetera
Caligula's abandoned invasion of Britain is linked to the possible creation of a legion later destroyed during the revolt of Civilis.