Complex sentence: These two legions were mauled so severely that, according to Appian, all of its tribunes were killed and their eagles taken by the Nerviians, and even the'primus pilus' had fallen to Boduagnatus' personal retinue.
Split into simpler sentences: These two legions were mauled so severely that, according to Appian, all of their tribunes were killed and their eagles taken by the Nerviians. Even the'primus pilus' (the senior centurion) of one of the legions had fallen to Boduagnatus' personal retinue.