Belgica Prima had Treveri ( Trier ) as its main city , and consisted of the eastern part .
Later Emperor Diocletian restructured the provinces around 300 , and split Belgica into two provinces : Belgica Prima and Belgica Secunda .
Belgica Prima had Treveri ( Trier ) as Belgica Prima 's main city , and consisted of the eastern part .
Later Emperor Diocletian restructured the provinces around 300 , and split Belgica into two provinces : Belgica Prima and Belgica Secunda .