 Maximian allowed a settlement of Frisii , Salian Franks , Chamavi and other tribes along a strip of Roman territory , either between the Rhine and Waal rivers from Noviomagus ( Nijmegen , Netherlands ) to Traiectum , ( Utrecht , Netherlands ) or near Trier . These tribes were allowed to settle on the condition that they acknowledged Roman dominance . Their presence provided a ready pool of manpower and prevented the settlement of other Frankish tribes , giving Maximian a buffer along the northern Rhine and reducing his need to garrison the region . 
